Regarding auto detecting jQuery, as one approach it could be present although hidden in BS5 projects. So it would just work concerning components, snippets, etc. Since the in-app preview and export are two separate things the app could simply look for jQuery references upon export. If there are any found then it includes the library as part of the export and if not then it omits its inclusion. There could be various ways other ways this could be automated the above being just one approach. I hate to keep referencing another app but I think that’s essentially what Blocs app is doing with Bootstrap v5?
With 5.7 it will eventually include “Improvements to Online Components - They will be organized info frameworks BS3, BS4 and BS5, so you can easily find what you need.”
Which I hope will help people from mixing and matching across versions as that seems like another rather messy situation waiting to happen in various regards for users.
This poll appears to be a toggle itself at 50 / 50.