BG3 might have multi-classing, but with a level cap of 10, it will be really questionable if it's worth bothering with for anything except Warlock 2 - 8 Something Else. If you take a third level in any class, then - rules as written - you will miss out on the level 8 Feat/Ability Score Increase. Most classes get their cool archtype with features at level 3.
I have 8 builds on D&D Beyond I want to eventually play after full release. Only two are single class, an Enchantress, and a Light Domain Cleric. And I may mix 2 levels of Evoker in with the Cleric. Most are 1-2 level dips, but 1 is split 5 Hexblade/ 5 Abjurer. That is IF Hexblade ever makes it in the game. I have one that is Death Domain Cleric 1/ Necromancer 9. But if we get an expansion that only goes to level 15, I'll consider taking the Cleric levels to 6.
