Settings for recording ps5 gameplay with HD60X onto Mac M1

[ac6]

I am recording ps5 gameplay footage from the console running at 4k, with the Elgato HD60X plugged into a 2021 iMac M1, the 8 core cpu 8 core gpu version.
I have recorded various videos but am just wanting to get the best settings for uploading these to YouTube. I have my base canvas set to 3840x2160 and have tried various downscales to 1440, 1080 and tried recording in 4k at 30fps.
I have then had these through DaVinci and exported them in 1080, 1440 and am doing one now in 4k.
What will give the best quality on YouTube for these videos?
I am recording in .mp4, running the Apple VT H264 Hardware Encoder, CBR rate control at 45000kpbs bit rate, 2 keyframe interval and high profile. Im relatively new to recording so anything I'm getting wrong here any advice would be appreciated.
I can give any more information if needed, I also found that the obs recordings were too dark but I've made this better using the colour correction filter on the display capture source through obs.

 

[ac6]

Can anyone give any advice on this?
Im just basically wanting to know what I'm best recording in, editing / rendering in to upload to YouTube for the clearest quality. I think Im right in thinking that the HD60X won't capture on 4K60? So I have recorded a 4K video at 30 which looks ok but I did also record a video where I put 2560x1440 into the output resolution but this also looked like 30fps when I played it back, id probably rather record at 1440 60 if possible as long as it looks clear enough, but just want to find the best settings for doing this regarding OBS settings such as bit rate, encoder with this hardware etc, then ideally to edit and render in DaVinci and what to render it out in.
Thanks.