Curiously after you asked me this I also tested my trackpad a bit more and it turns out that if I go slowly from off the trackpad onto the trackpad it doesn't register the touch at all.
Not sure if that's some kind of feature intended to prevent accidental touches or a bug. Never noticed it before in my ~7 months of use.
I’m pretty sure it’s a software thing whatever it is because I don’t get the same behaviour in the BIOS pages. The trackpad is pretty choppy there for me but it is sensitive at the edges.
Out of interest what trackpad driver does xinput report running for you?
Mine is a Dell07E6. I’ve wondered about switching to the older Synaptic one.