I'm not a big QD user, and I rarely use a drying aid (relying on the rinseless polymers for drying lubrication). If you like using Opti-Seal as a drying aid, going over the car again with a QD a half hour later doesn't make much sense to me. I don't see what you're gaining with that (I have IDGE, although I can't remember if I've ever used it, and it does have that fluoropolymer additive that maybe gives it a slightly different characteristic than the Opti-Seal and most other QD's).
I might be more inclined to do it the other way around but I'm just talking off the top of my head. You might also consider washing with ONRWW, which gives you some "wax" for drying lubricity, it's what I usually use these days. Then you could go over the car right after that with the Opti-Seal, and skip the "30 minutes later" part. But if what you are doing is working for you, there's nothing wrong with what you're doing, I'm just pointing out things that might be redundant or could save you some time.