should I plate the frame for coilovers?

Yes, I would plate the frame. I would plate it from in front of the steering box back towards the cab, with some large plug holes in the center. 1.5" or so. This will keep your tabs from tearing off your frame. The tabs on a coilover are placed much closer together than a bag is, and built in a different way. Depending on where the bag plate lands on the frame, sometimes I will plate the frame for bags as well.

This is what I am talking about with a plate and plug holes. This will give you a better surface area, and will not tear your frame in the future.

I ended up not plating it. I think with how smooth the coilovers fuction and how much of the abuse they handle it should be fine. I filled the top of the tabs in and welded those to the inside edge of the frame so its almost like the bracket spans 3 surfaces. the front wheels should stay planted unless I add a supercharger later on.