If it's interpretations of Farsight that you would like to see, then I can certainly deliver! :D
Even from the little that we see of her in canon Farsight is definitely an interesting character by premise alone. She seems to be very nice, kind, and caring, while stuck on an island that very much is not and has drifted away from those values in its culture as a result. She's the mother of Fierceteeth, who has a polar opposite demeanour, and her other child was taken away as an egg from the prophecy.
From what we get of Secretkeeper's testimony, she's also very forgiving, to the point that SK doesn't worry about Farsight maintaining hurt feelings after she says something cruel (and secretly hypocritical) to her in the Moon Rising prologue. My interpretation of this is that she's a people pleaser, to some degree, even if it hurts her. It would make sense given her circumstances: everyone is suffering, so she came to the conclusion to try to minimise the suffering of others. The state of affairs has also brought out a cruelty in some, and so trying to be as polite and nice as possible is also a possible response to avoid that.
It's possible to infer a bit more about her from her relationship with Mastermind. Mastermind is an interesting character in his own right, but what's most relevant here is that he is (presumably) well meaning yet temperamental and has very poor social cues. What exactly made them fond of eachother is hard to know precisely, but I definitely have my list of headcanons.
For one, Farsight was definitely smart. Mastermind probably wouldn't have had the patience to get to know her if she wasn't an academic equal or near-equal. I also headcanon that this intelligence was something she undersold about herself to appear nonthreatening because of her people pleasing tendencies, but it came out around Mastermind regardless because he has limited fields of interest and so things that required her to demonstrate it would come up in conversation. We already know she was forgiving and presumably patient as an extension, which would've made her able to navigate his quirks more easily. She must've also seen some traits in Mastermind that drew her to him-- the altruistic nature of his work and inventions (as mentioned in your fic!) was very likely one. I also like to think she was endeared by him being a bit of a dork and thinking that was sweet. And, having someone who she could let down some social barriers around (since they were meaningless to him anyways) is probably something she would find pleasant. The version of her that I imagine is definitely a likable personality. Very sweet.
One interesting thing about Farsight is, despite being remarkably kind and gentle for her circumstances, is that she definitely wasn't a saint. Her relationship with Fierceteeth seems to have had some very real struggles to it-- she was preoccupied with Starflight's egg when Fierceteeth was young, which led to some disconnection, which according to Fierceteeth's section in Winglets was never really recovered from. Fierceteeth had some childish jealousy over the attention going to the new baby, a fairly routine scenario, but then everything was complicated by the prophecy and the egg being taken and so it was never resolved like it should've been. The interpretation this implies for me personally is that there was some kind of favouritism involved, presumably subconsciously. We know very, very little about Fierceteeth's father, other than the fact that he died before she ever hatched. It's possible that Farsight's relationship with her daughter was either tainted by his death, or her relationship with him entirely-- it's all too easy for someone with people pleasing tendencies like hers to end up in a bad relationship. Meanwhile, Starflight's egg was something she was very attached to, to the point of being (by my reading) in denial about it being taken. Like, if Morrowseer is able to know that this egg will hatch precisely on the brightest night, anyone should be able to tell. (It is a massive plot convenience in WoF that dragon eggs have down-to-the-day perfectly predictable gestation, by the way, but then again most of the biology is like that. Needing a little extra suspension of disbelief is part of the charm!)
Farsight is also very, very full of potential when it comes to the sheer angst of her character. She's stuck in a kind of ambiguous grief that very few dragons around her would be able to understand for, as far as we know, the rest of her life after Starflight's egg is taken-- she knows he's somewhere better than where she is, or at least presumably is, but she'll never know his exact status or location or well-being or anything about him. He's alive, and so she'd feel bad for feeling so strongly (an 'other people have it worse' mentality) on top of feeling bad because. Her child was kidnapped for the greater good. The other parents of the dragonets of destiny had their eggs kidnapped, which they had to deal with, but there's a sort of knife-twisty-ness in Farsight's specific case because she knew it was coming, knew she couldn't resist for the sake of all of the NightWings' survival, had to do it "voluntarily", and still didn't want any of it. Unless she was really, really going through it with the denial that her egg would be taken it's toatlly possible that Starflight was never supposed to intentinally been a prophecy egg, but ended up perfectly in the time frame by coincidence. Which is uh. A gut punch and a half.
I will never get over the Moon Rising prologue, by the way. Secretkeeper really told Farsight that her honest and earnest attempts to consolidate her were inconsiderate and ignorant because she had two perfecly healthy dragonets, one of which being raised on the mainland, as an excuse to get away to make the hatching of her perfectly healthy dragonet who she faked a miscarriage / the egg equivalent thereof to deliberately raise on the mainland. Like, Fierceteeth was stuck on the island and it was in jeopardy if Farsight would even live to see Starflight one day. Secretkeeper had knowledge of Moon's wearabouts and general life existence-- sure she had to sneak away to see her but this was an arrangement she more or less chose. Like, Secretkeeper!!!! Girl!!!! You better have given a damn good apology, especially since it would be impossible to undo even close to all that damage without revealing your secret (which honestly might've pushed even Farsight over the edge into crashing out at her). And, based on the vague and rushed and weird canon timeline (again suspension of disbelief adds ✨ flavour ✨) , Farsight literally died not long after this. Secretkeeper and Farsight's friendship is very interesting to me because of the sheer "oh my god what the hell" factor that scene has. I also have the VERY evil headcanon that they're uh. Exes. And part of why Farsight has maintained attachment despite everything is because she hasn't fully gotten over it. They can be just as compelling platonically too ofc!
ANYWAYS, now for a more mundane, less depressing headcanon: Farsight's occupation! Yayyyy!! My current headcanon (not a particularly strong or defined one mind you) for what her job was is that she was a lookout, mainly because. Her name. She was looking far away or something. (Her name could probably also symbolize thinking about her missing child who was living somewhere far away I suppose? Just thought of that now.) It also sets her up to get killed by SkyWings a bit more obviously but disregarding that for now! Your interpretation of her being on the council is super interesting too, and it makes a lot of sense for her character-- especially the way you write her! I've also seen a fic where she fixed clocks for a living which is cool. A bit of a random choice but a cool random choice. I've also had an idea that she could be like a scribe sort of, recording information or something. It would fit with the 'smart but pushed to the sidelines' sort of thing I have going on with my headcanons for her.
Hopefully that was coherent! I am incapable of brevity as you can see here, and this isn't even absolutely everything if you can believe it. I have a few outlines sitting around for Farsight-centric stories to better show off my interpretation, but none are polished enough to see the light of day as of now. Ideally I'll be able to write and put out something to share more Farsight appreciation with the world in the near future.
TL;DR: Farsight is super interesting to me on a conceptual level, and I have a few ideas for her personality--mainly that she was a people pleaser, among other things--based on what is available in the text. She has compelling appeal, compelling shortcomings, and compelling angst. Also SECRETKEEPER IN THE MOON RISING PROLOGUE AHHHHHHHH