I find the choice of modifier keys to be quite unconventional, at least for a Windows user. Other design programs, such as the Adobe suite, uses ALT to resize around center and CTRL to break out of snapping. Affinity Designer for some reason uses the inverse of that.
This is really troublesome since Affinity Designer isn't the only tool I'm using, so I'm not getting "retrained" either.
Feature suggestion: let the user be able to customize which keys should modify what behaviour.
I'm also suffering from this bug (Desktop version on Windows 10). Please move this up on your prio list, as expanding strokes is a super common thing to do.