I think we tried this library a while ago and it had some problems, though it was a year or something since then so maybe it is better now.
Also, I’m really not sure if this library actually switches threads in iOS, I only barely looked at the source code and I couldn’t find anything that creates an additional JS thread or switches to it.
I did profile the app and then the JS thread was indeed clogged and mostly because we had to process each message coming from a mailserver in JS. Theorizing about performance bottlenecks is a pretty unfruitful endeavour.
I think we have an option move down a level some of our code and just go multithreaded when we need that, since we have quite a lot of the logic already implemented there. If we just were a “pure” RN app, it would have make sense to look for a RN library for that. But we already have status-go and some API that we expose, so I think we should use that.