You can automate mask rendering in substance designer for example, then use photoshop script to batch combine all textures from a folder into single texture, merge and bleed it. Unfortunately I can't give you exact steps, so if time spent on research and automation is worth it depends on how many textures you need to…
the problem is that painting all of them at the same time is a pain in the arse. I wrote a painter plugin that does it for me because I can but if you don't know how to do things like that then Dimwalker's suggestion is the best option. Set up an export preset that dumps a mask out along with the textures and then use…