This is because artificial leathers (not yours) tend to be made of PVC, which will destroy your machine. Check out #4:
Your polyurethane leather should be ok (I’d get Trotect to tell you with absolute certainty that there is no PVC in it, but the claim that it’s 100% PU seems to lay that to rest), but like any plastics-based material you should be aware of the risks and monitor the jobs carefully.