Would installing an OS on an external ssd and booting into that to run pirated software while blocking access to other drives in your system or physically unplugging them be one way?
Or are there better ways to isolate the software you run and use as much as possible?
I haven’t seen your stance on VMs, but a lighter approach might be confining the software to an AppArmor profile or such. The kernel will enforce the restrictions on what it can and can’t do.
It won’t have the overhead of virtual machines, and you can keep using a single video card, but setting this up is quite tedious, though.