Upon investigating your MinIO set-up I had an obvious idea:
“Can I just open the address of the video in my browser address bar?”
Yes, I could!
“https://minio.eom.dev/public/Videos/2025-08-26_20-32-29.mp4”
Worked beautifully with zero buffering. I’ll just do this from now on. 
I was recently discussing using PeerTube to host my videos, so it is interesting to hear that going directly to MinIO is beneficial. [1] It makes me think that it may be better to continue with my current workflow of uploading to MinIO and then embedding on Discourse and Gitea. MinIO has a tagging feature that I should probably start using to reverse link the video to where it was shared publicly.