I used NOS for several weeks, and I had a very good battery life, one of the best I ever had on OP3. I don't think the battery problems are rom-related. NOS has also very good performance, is very stable, and contains all required features for my needs. I switched to RR last week, it is very good also, seems very stable. I found battery is maybe slightly worse than NOS, but idle drain is very good (I lose 1 or 2% a night, with all on), and I found some features are missing but surely will be there in next updates.
(FYI: I am using OP3, decrypted, EXT4, magisk 15.3)