I think part of the disconnect between Sinder and this platform is that, in my opinion, she doesn't get turned on by showing more. She just gets embarrassed. So, instead of being a gooner's paradise, it becomes a Twitch stream where she can be more of a tease for those who pay tons of money- have a few moments of personal discomfort to appease the gooners, and then continue on like nothing happened.
Think about it: if she actually got turned on by anything she did on stream, do you think she would stop? Especially when doing more is generally expected on this platform?
So, if and when the new Fansly model arrives, I wouldn't expect much of anything beyond the debut stream. Best bet is it becomes like Spite's streams with Sinder's model full naked dancing and IRL Sinder being fully clothed and uncomfortable. I wouldn't expect gooning ever. She has said she lasts less than 10 seconds before, and if she's not into overstimulation or going for multiple orgasms, I can understand why she would feel that it would be a disappointment. I mean, imagine you paid $100 just for an avatar to quicken her breath and moan "I'm cumming" in 6 seconds and then take away the vibe for the rest of stream. True, that'd be more content than she's ever given, but it seems so easy to fake that she probably feels like she'd be scamming the fans (ironic because she still is doing that).
Anyways, holy essaying, apologies!
Tldr; Sinder won't show more because she isn't turned on.