What does their multi-device story look like? Can I use one identity/account on multiple devices, with synced read state etc?
Edit: Looks like it's being worked on. I don't want to use a messenger without this feature anymore, but I'll give SimpleX another look once it's done.
It's planned to be 100% API compatible with Lemmy, so you'd be able to use any Lemmy-UI with it. IDK why LW or any other instance would change their default UI.
A lot of things are not final and may change, but let's just start with their stated goals, instead of speculating about all the things that could theoretically happen.