I'm having the very same issue here.
As Chinese using Chinese input, I frequently press the 5 or 6 digit key with my left-hand point finger to select the Characters.
And every time, every freakin' time!! I end up with ghost touches that ruined my input.
How come, just how come, in 2022 already, does MacBook not have palm rejection......
There is a solution though, which is to buy a skin, that covers the top part of the trackpad, the part that might be unintentionally touched by the palm or the thumb finger.
it's like helping rocket science with a wood stick yet somehow it works...