Both posts are good input, thanks. I've wondered about just individually replacing the 1.5mm spokes with 2.0 spokes on the rear wheel. Is that possible? Doing one at a time replacements? Or is it better to just unlace the whole wheel and start over?

Does the hub factor into wheel strength? Meaning, would a wheel be stronger with a DT 350 or 240 hub rather than an Ultegra hub if all other components were the same?