I'm currently planning to run Abomination Vaults after my group finishes the beginner box. I wanted to keep using my homebrew setting from when I used to run 5e, so I've started a document in Notion with conversion notes. Basically any time as I'm reading through AV I notice something that doesn't jive with my setting, I make a quick note about what I'm changing.
The main change I need to make is the stuff with cosmic entities. My setting is a bit like Eberron, where there's no real proof of the existence of Gods or religions. Nhimbaloth is probably going to change from being an "Outer God" to being a Lovecraftian Great Old One. Not sure what to do yet with the devils that come up in the second book.