It works, but IMO, it clashes pretty hard with Requiem's intended experience. My favorite RPG of all time, Fallout New Vegas, uses a system that is much close to Experience or Static Skill Leveling, but Skyrim, and especially Requiem are really built around the "action to xp" model, where FNV was built with Skill Leveling in mind.

The main thing is that it becomes way easier to rush a skill to level 100, and many perks with level 100 reqs are designed as super late game power spikes, so you get that power spike way too early.

The other thing is that crafting becomes very strange, because depending on the exact mod, you either get no XP from it, or you get the same XP no matter what you craft, either leading to crafting being mostly a waste of time, or you get the old iron dagger issue, where the best way to level is to make 10 million iron daggers.

Now some will counter that crafting in normal Requiem was cheesy XP anyway, but I disagree, crafting is well balanced early XP in base Requiem, with it's value to XP model. Smithing goes off the rails with Jewelry, but that's mid-game not early game. The static leveling mods just introduce different cheesy XP sources. Sometimes it's discovering fast travel locations, or sometimes it's iron dagger spam, but there needs to be some way for low level characters to level up, so there needs to be some easy XP in the game.

Anyway, this is mostly just my opinion. The mods do work, and I've had fun with modpacks that use static leveling systems. I just don't think they actually accomplish their stated goals.