Increase drag start distance
I understand that you don't want to expose more configuration options, and all in all the provided defaults and exposed settings are fine for me.
The one thing that annoys me every time i try libinput instead of evdev for my mouse is the "Drag Start Distance" (at least, that's what it's called in KDEs system settings with evdev).
There are many threads about this to be found in various forums, but they all just resolve it by using evdev. And as evdev afaik has no future on wayland, i think this issue should also be solved by libinput directly. And i'm kind of surprised that it wasn't yet filed here.
To clarify: when using libinput, i often accidentally select the topmost entry in a contextmenu by simply rightclicking because i moved the mouse a few pixels and it was interpreted as a drag-action, so when releasing the mousebutton, the highlighted entry is selected.