Yaarel
🇮🇱He-Mage
Maybe the Nonproficiency bonus = Proficiency − 2?Eh?
The point of issuing a new edition after frikkin ten years should be more than polish, and we should question "change around all the details so our compatibility promise doesn't really tempt people to stick with the old stuff".
Tell your "half edition" to the 3.5 folks instead - that edition came just a couple of years after 3.0, and quickly and conveniently obsoleted a deluge of 3.0 splatbooks.
We shouldn't have to wait until 2034 until fundamental things like how your level 20 character still sports a +0 Int save are patched, or how there still isn't a functional gold economy in 5E.
So at the Apprentice Tier (1−4) the Nonproficiency is +0. But at the Master Tier (9−12), it is +2.
This simple fix keeps the d20 Tests proportional at any Tier, even Epic.