So, here's the thing - no matter how differently written Stolas could possibly be, I just don't think he and Blitz have much ground to stand on as a long-term relationship. They have nothing in common except sex and a questionable devotion to their daughters. I can't see them taking the time to become invested in each other's interests (especially not Blitz).
I'm personally not particularly invested in Millie and Moxxie's relationship either, especially after more recent episodes (Unhappy Campers being the biggest offender). Recently there was a poster released on TwitteX to promote a Helluva Boss VA panel, and front and centre is Millie and Blitz essentially bullying Moxxie (they're at a swimming pool and Blitz is sitting on Millie's shoulders trying to pull Moxxie's trunks down) and Millie looks... disturbingly happy about the possibility of publically embarrassing her husband. I'm probably reading too much into it, and the residual saltiness of Moxxie being HB's punching bag is colouring my view, but something about them feels rotten at the core despite being really bland on the surface.
Moxxie and Stolas together, however, I think have a little more going for them. Only if some drastic changes are made, though.
Here's the idea - in this world Millie and Moxxie aren't married; Blitz still makes the full moon deal, but the requirements aren't sexual.
Stolas is lonely and miserable. He thinks of Blitz as his only friend and wants to resume the relationship they had as children (not quite understanding the circumstances surrounding that single occurrence) - Blitz doesn't give a shit about Stolas' rich boy feelings and only wants the grimoire. He agrees both to IMP being Stolas' main hit squad (of which he won't have to compensate) and also to a plea for companionship. However, at the last minute, Blitz sends Moxxie in his place instead of visiting Stolas himself like he said he would.
Blitz and Moxxie barely have a functioning relationship in the show as it is, and I've decided to lean into that. Blitz considers Moxxie to be a bit of a wet towel and sends him to deal with the big blubbering bird man instead. Moxxie puts up with his behavior because it's marginally better than being under Crimson's thumb; at least this way he's getting paid.
"He's kind of a pansy like you, Mox. I'm sure you two will get on like a house on fire - now fuck off and don't screw this up for me."
Stolas is, of course, massively disappointed, and Moxxie can tell. They figure that they'll make an evening of it since Moxxie is already there (and that later Stolas will reiterate the fact that he requested Blitz's company specifically) but they end up finding out they have more in common than they initially expected - they both have a huge appreciation for music and theatre, they tend to err on the side of dramatically intellectual, and they both have parents who despised their natural soft natures and wanted them to grow up far too quickly.
Moxxie takes Stolas (in disguise of course) to see a musical he's very fond of and is delighted when Stolas genuinely enjoys it - Stolas invites Moxxie to an opera and Moxxie is starry-eyed since he's never experienced something this far above his tax bracket before.
The other thing that kind of bothers me about their current relationships is this emphasis on aggressive lust (Stolas and Blitz's questionable BDSM practices; Millie and Moxxie carelessly doing it on stage in front of a news crew) that makes it slightly hard to believe that these couples do anything with each other outside of having wild sex. I feel like Moxxie and Stolas would be able to formulate a softer love that would challenge their experiences on how one experiences healthy affection.