"and unlike a stand, he must obey the laws of natural physics, and would most definitely blow up the earth with one single attack lol"

When has this ever been an issue in any anime? your point is to apply real world physics to a verse that doesn't operate under them

Oh boy here we go. I am completely aware of the fact that things such as that don't really apply to fiction, but it still has complete 100% relevancy. You can simply fix things by making a new rule that says "He also follows under the logic of a stand and will not blow up the earth with his MFTL+ attacks".

That's the assumption, does either have a planetary feat off speed? no, so thats not a factor here

A jump from slightly FTL (being at island level) to MFTL+ speeds would definitely put him at a planetary+ category, so that error is kind of on you.

No it's not, and typically equalization scales down

But fine, assume they are in an indestructible void, with everything needed for life, and stop derailing from the fight

Additionally neutral territory, both have the full range of their abilities that are in character, before you try and talk out of this one, stats are still equalized

Much better. It is a smart idea to create an indestructible battleground when you try to do an "Equalized stats" fight.

So that misconcpetions and confusions like these don't happen. Remember, we can't read your mind.