My two cents...
OP entire story smells of BS. Someone can't, or won't, or never in the first place payed for software, and now no one knows how to crack something newer that will work. If the machines were working adequately on gt 210, why get RTX 4000, or why upgrade at all?
"because we plan on putting in more cnc machines in the future" Nope, not buying it. You don't buy gpus now for an upgrade that may come at some undetermined time in the future. Whoever is responsible for the IT screwed up.
This is an easy to solve problem, but you won't do it. If you already are using old, unsupported equipment, then just by old, unsupported replacement gpus that you can get old, unsupported drivers for. Can get quadro p1000's for like 100 dollars a piece that will smoke a gt 210 and have driver support back to windows 7.
1507 and 1511 work but 1607 doesn't? I don't think I believe that.
None of this makes sense, and I don't believe we are being dealt with honestly here.