I have tested the welding of these in place with a few small tack welds, and it works great. I mig weld, so ruining the temper of the heat treat isn't an issue because the mig doesn't heat up the piece at all.
I have done several this way.
For people saying 'ease of replacement' with the rivet, it's actually much more annoying to chuck it up, and mill away the old rivet, set up the press, and re-press a new rivet.
cutting a weld and rewelding takes literally 3 minutes.