Non-dominant hand (some folks don't have a "weak hand"
) manipulation and shooting is good to learn and practice.
I once decided to do all of my training left-handed for 5 months (including quals, even when off-side/non-dom drills weren't required) while working as an instructor. I didn't switch out holsters, but just transitioned hands after drawing or practiced reaching with my other hand (as if my dominant hand were injured).
One of the interesting observations I made was that it was no longer surprising why our left-handed shooters didn't ask for their RH mag catches to be changed over to LH (once we'd adopted models that allowed it), but remained with their left-handed manipulation of right-handed catches. Actually easier to do with a LH finger than a RH thumb. Ditto dropping slide stops that way on
some guns.
Practicing with the non-dominant hand when it comes to shooting skills makes sense, but that was something drilled into me as a young man when I first started in the martial arts. Deliberately becoming a fighter who only possesses skill for 1-handed blows can be really limiting.