I might remember this wrong, but I was under the impression that mix-to-video is coming in a later version that will be paid.
I’ve found Resolve to be a good software and I’ve used it to lay back audio to video. Obviously it’s jumping through an extra hoop, but on the flip-side of things it allows for batch renders.
On that note: I’m absolutely shocked at the efficiency and speed at which Blackmagic Design is spitting out software updates. For an actually professional software that’s free it’s absolutely astounding.