It seems to us that switching to Rclone doesn't give any indication that app is doing the switch (e.g. no loading icon, no blur etc.), but in principle tapping once and waiting little bit should be enough (no mashing required).
We'll aim to improve UI, so it's clear that app "does" something. We'll review this part of the code to see if we can switch faster.
Can you try tapping once and waiting a short while to see if switch happens anyway?
Thanks! (edited)