Personally, I find my watch tends to sit above my wrist, so it's not over the palm rest at all.
In other words: This is how reality works. And here in reality, the buckle is annoying. Speculation as to its annoyance in an alternate reality is beside the point.
I've had carpal and nerve issues in the past, so I watch this a lot... generally you can drive the better habits simply by reconfiguring the work setup.
But all of this is quite irrelevant when one is talking about the inherently non-ergonomic use of a laptop that only happens in meetings and hotel rooms.
http://mindfulmotionphysicaltherapy.com/what-is-an-ergonomic... (For info purposes - not endorsing this particular practitioner.)