Nuts and bolts are installed 2 at a time, one in each hand.
I have tried to do some right hand training, such as writing. My left hand writing is atrocious anyway, just block print, forgot cursive long ago. Never held a pencil correctly, finger always hurt, 3rd grade teacher was Methusalah's mom and despised lefties, etc, etc.
Welding is kinda funny, I forced myself to be ambidextrous. Most everyone defines their hand by the torch hand. I had to switch because I could not finely control the rod with my right hand. Now I probably do 75% left hand but have no issue with the right.
Working your weaker hand is great if you play gun games, if weak hand shooting is indicated you can look forward to it while everyone else groans. Of course that's not much different than stepping up your game when it is raining, 20 deg, muddy, 30pmh crosswind, or 99 deg. Embrace the suck.