This is excellent work!
I am trying to achieve a somewhat similar color grade / look with a promo I shot for a client (that Nike commercial aesthetic).
I also had to resort to shooting between 3200 and 6400 ISO due to limited lighting, and had some reservations, but it's definitely reassuring seeing how great this looks!
If I may ask, did you do your sharpening during the de-noising process, or did you save that for the very end?
And when you say you compressed to h264, did you do that using the export settings in Resolve?