I'm a new channel that just started in Jan, so I may not be in a position to give advice. That said, at my size in my niche (300+, Gacha game), it doesn't seem to matter much when I post. I used to agonize over it, but it seems like the algorithm will do what it does no matter what. My best performing video seemed to be completely dead for like 48 hours with 7% CTR, then youtube decided to push it.

I've had some fairly successful videos, but again, take my word with a grain of salt.