That's the same journey I went on, 10K -> RKC ROP and I really enjoyed it. I think you will too.
There is a lot of posterior chain work in RKC ROP, so your hamstrings should be good to go, but you are correct that there's not a lot of quad work in there. Since the program has two variety days to just kind of do whatever you'd like, I did a lot of goblet squats to make sure I wasn't losing anything in the legs. The recommended Turkish Get-Ups in the the second variety day will help you a bit too.
Besides goblet squats, another excercise I'd recommend to really hit your quads is one I just learned from Joe Daniels: Somersault Squats: https://www.youtube.com/watch?v=OxwJja4rr4M
You can go very heavy on those compared to goblet squats because all your arms really have to do is hold the weight, you don't have to get them up and held by your shoulders.