I was wondering if there was a way to add the corrosion mechanic to non-betweenland tools and weapons? I know there is a slow mechanic, but I wanted to see if you could add a way for us to have that off but all tools suffer corrosion instead of the slowness.

The main reason I'm asking is I'm trying to use betweenlands with other mods in an integrated modpack that has a lot of mod features working together. Having the corrosion effect apply to all tools and weapons would be a huge step forward.

Technically yes but it'd require a rewrite of the system. And adding the corrosion overlay to other mods' items could be very tricky.
This is definitely something I'll consider when working on the 1.13 port though.

Hmm...too bad. Well at least it could be a thing for 1.13. I'll just have to figure out something else for tools and weapons. The goal of this modpack is to have the player digging deep through each dimension to eventually escape, and one of my internal goals is to always keep as much of a mods gameplay mechanics as possible so the player gets a good feel for each.

I'm just trying to tie everything together into a cohesive story using multiple dimension mods.