I have a theory that the RSI is mainly developed by the angle of the hands relative to the keyboard. Which is why the profile change is sufficient to mitigate the problem.

Good point - using a wrist rest with a mechanical keyboard feels a lot more comfortable for me, since they tend to be a bit bulkier and more raised from the desk. Without one, I rely on the armrests to have the forearms higher than the keyboard so that my wrists aren't flexed.