Bottom bar collapse exists the other way, some users prefer to not see the bar by default and then you can hold to show the bar.
I definitely wanted to make, tap/hold actions fully configureable. It's somewhere on the backlog, I'll create an issue if it doesn't have it already.
The swipe gesture feature uses a new experimental component. As far as I am aware we can't configure the sensitivity. We have decided to have it off by default. We also fixed the swipe direction not being aligned with the description.