I've always loved IFS, but I think my biggest problem with it is that it leaves you wanting so much more from it. Devi is an interesting character, and giving her depth outside of getting almost stabbed is a good premise for a spin-off, but I feel she doesn't get a lot of breathing room as herself outside of how she's responded to trauma, and said trauma by extension. It's supposed to have her art, and her relationship with it, as the central focus of the narrative's conflict, but her paintings are only ever in the background and her individual relationship with it isn't expanded upon. What's inspiring her? What are these images which she's so desperate to get out of her head? How does she process the events of her life through painting? I'd like to make a post getting screenshots of all her art throughout the comics and attempt to figure out an answer, but you wouldn't get one reading her comic.
It's implied that Devi throwing herself into her work is a compulsive behavior born out of self-avoidance, at least in part, so I think this might be an intentional writing decision. It definitely leaves the ending in a bittersweet place that I find interesting, and realistic all things considered, but considering the fact that IFS dwells on this complication so much it does feel strange that the overall resolution that it comes to is that Devi's incapable of finding social furfillment, and the solution is to continue throwing herself into painting. I find it compelling that it ends on a note that's more complicated than Devi triumphing over Sickness, and magically becoming a different person through force of will. However, if she was intended to have a semi-static development, with IFS being a window-exploration of the end point she's reached more than anything else, it just would've been nice to have her art be a bigger part of the comic for that purpose. It was basically a ventpost about working for Nickalodeon though, or at least that's the impression I got, so I'm not surprised this ended up getting sidelined.
I think JV saying that IFS's outcome is slightly happier, and drawing a comparison between Johnny and Devi, is telling in regards to what he was going for with the two issues, and especially IFS's ending. However, I feel that showing Devi's old paintings, or having her talk about them a little in specific, wouldn't have cut into his intentions. If she's bottling up a life's worth of bullshit, and has adopted an avoidant or misanthropic perspective, then her art would've reflected this and could've expanded upon that part of her character in a way that didn't revolve around another character. JTHM even does this with Johnny, and his paintings, so it'll always feel a little strange to me that the comic about reclaiming your will to make art for yourself only brushes up against the art that Devi makes for herself. It's like she's absent from her own story, and it's because she's supposed to be disconnected from herself, but I feel like this could've been executed in a way that still allowed her to be more of an actual character. IFS is carried more on JV's abilities in writing really good dialogue, and generating interesting ideas, rather than the depth of those ideas-characters themselves, in my eyes.