How can I improve my straight flying skills on 60hz without using the bypass or 144hz?

Basically, I'm trying to beat Quest For Perfection ATM (65% & 42-100 are my best runs) and I am extremely consistent at every part but the straight fly. I have put twice the amount of attempts into it than any other part, including the duel, and still die there >85% of the time. Also, if you're wondering, I don't want to use the bypass because I have OCD or some shit idk but I will get really frustrated with myself because I guess it just doesn't seem real enough. (Don't try to change my mind, nothing will work)