Hey Mork,
The world of Aenor has been a persistent campaign world for over a decade, and is the place in which all of my campaigns are set.
Historically, I used the industry front runner RPG, or the derivitive “-finder” game, and even dabbled in D10 survival system, trying to find something that mechanically could match the flavor and fluff options of my world. Of course, that requried substantial amounts of homebrewing, because “Caves & Crawdads” did not include magitech, steampunk, gunpowder, alchemy, or the races I had come up with. The gods are undoubtedly real, but aren’t the same gods as in the books. Sometimes a wizard specialized in frost magic in his backstory, but the majority of spells were fire typed, so he was stuffed. Of course, I just homebrewed it all, which I found enjoyable, but then I had to edit and provide campaign supplement booklets to all of my players with the setting specific races/classes/equipment etc. so they had the crucnh to match the fluff.
Open Legend set me free.
Of course I still provide the explanations for the races, and gods, etc so the flavor is there, but I don’t need to make up the crunch. The genre-bending abilties of OL, which are excellently showcased in Amaurea, were a perfect match for omni-genre, silly-serious, melting-pot kitchen-sink setting I had built over a decade.
P.S. - Really nice topic 