Several of my pals are shooting powder coated bullets of various colours in their .45 and 9mm bottom feeders. Some have tried them in BPCRs as well, claiming good results.
I doubt that they will sustain a long string without some issues, but I have no experience so I can't say for sure. I do know that when it's hot and dry here in the summer, both PP and grease bullet loads require a bore wipe every 5 rds and a chamber swab EVERY rd for best results.
Like smokeless powder, this powder coating is just a passing fad .....