Many of our early hardware providers (hosts) are crypto miners, as they often have many graphics cards. As a result, we pay our hosts in crypto in order to attract them to our network. Our software, rentaflop miner, doesn't behave like a normal miner, however. Its goal is to take existing cryptocurrency miners who mine currencies like Ethereum and give their hardware more useful work such as rendering.
Are you experiencing significant performance penalties due to miner use of 1 lane PCIe risers?
I did some testing for a version of such a service in 2017 and it was determined the typical GPU miner configuration using x1 PCIe risers reduced I/O throughout and therefore performance of GPU hardware to the point of being practically useless for anything other than mining.
I have no experience with the characteristics of rendering, I/O, etc but it seems this also applies.