Negative Xp Bonus Hypothesis

I heard from a person in the Lootrunner's Guild discord server, that if your XP Bonus percentage is below 100% (Essentially Negative EXP), then you will begin to lose EXP on mob kills and such. So I created a hypothesis on this matter, and it goes like this.

What would happen, if someone were to have -100%+ XP Bonus, set their guild XP to 100%, and then dungeon run, would they lose their guild thousands and thousands of XP per run? And what if you got more than one guild member to do this (not saying anyone would because it's an insane thing to do anyway), but hypothetically speaking, could you level down a guild? Or would it go back to 0% XP and remain on the level it was at?

Or is all of this baloney and XP Bonus has nothing to do with losing XP (either guild wise or in general).

 

Someone did a test

 

neat

 

However, they didn't actually test whether it brought down guild xp "I have not tested if this actually affects the total guild XP since there is no way to see the exact guild XP,"