https://mods.factorio.com/mod/electric-trains

Could we get integration with this mod?

It doesn't appear that mod requires integration? They copy the base locomotive vehicle grids (if any exist) during data-final-fixes, which is long after this mod has done its work, so it should work perfectly fine. They come early enough that it doesn't seem they need a bigger grid than that?

The electric speed booster you add isn't a valid item for the equipment grid. Though it doesn't show the exoskeleton as a valid item for equipment grid either =/

That's weird, when I tested the mod, I was seeing the speed booster as valid equipment for the primary locomotive. It's possible I missed the cargo wagon variation that is still technically a locomotive; I'll look into this later.