Not sure if to post it, but I hope it might be interesting to someone having similar doubts…
I compared the situation with one of my old videos.
Old version was exported using H.264 High Profile (with 44.1khz audio and lanczos). It had 80MB.
New version was exported using YouTube profile with the following modifications:
Export: 2560x1440
Interpolation: Lanczos (best)
Codec libvpx-vp9
Rate control: Average Bitrate256
Bitrate 20Mbs
Audio 44100
Codec libopus
Bitrate 384kbs
What I noticed in the log, this codec was not able to manage 44.1kHz audio and changed it to 48kHz.
And the size is… 2.6GB. Crazy!!! So the file is about 33 times bigger. The export time increased 6 times.
Even if h.264 high profile was probably too low quality for youtube, I’m not sure if I can afford this new settings. To keep the files on my hard disk I would need a lot of space. Also export time is insanely long… Thus I have to experiment with sth simplier… Perhaps using 2k resolution but standard YouTube profile settings (with Lanczos as the only difference) would be a better idea…
Edit: What I noticed that audio is missing in the exported file. Probably due to this problem 44.1/48. And video bit rate is depending on the moment, ex. 154343 kbps thus 154Mbps or * 223877 kbps thus much higher then set before export. Not sure why? As I set 20Mbps only.