I'd be surprised to find many guys that use more than normal TRT prescribed doses that do not have higher than normal HCT. I've had it for 20+ years. I used to go to the red cross a few times a year to donate. You can specifically donate "double red" or what I think they now call "Power Red". They take out blood, separate the red, put the other parts back in you, then do it again. What normally happened was I'd fail the initial qualification test for having off the charts HCT (when they prick your finger), then some manager would override with a code or whatever. I don't know if it ever really helped me but hopefully it helped someone else.
The last time I went was during the earlier parts of covid. for some reason, my BP was too high so they wouldn't let me donate. I thought that was really ridiculous so I haven't been back since.