I managed to fix the jump problems today. The jumps finally work correctly in all scenarios!
The fixes also made it possible to have your size influence other kinds of jumps like jump attacks.
It might not sound like much, but there were 4 separate bugs happening with the jumps. It pains me knowing I allowed that to sit for so long. I know these are WIP mods, but I do feel bad bad about having everyone deal with that.

I can also confirm that the issue with dying at different sizes is resolved!
Knockback when getting hit by attacks is also a bit more consistent.

Now I can focus on getting some new features into Size Effects to allow for more customization and visual details.