Everyone has a different approach. Weld, silicone, bolts and epoxy lol. I welded mine, the few that I missed im going to hit with a big glob of silicone
I welded all of mine so I would not have to worry about them later. But...it is a good idea to go underneath and shoot some rust reforming paint on the welds. That fresh metal can rust like crazy if not treated. Did all of mine in a few minutes.