Current SNARK provers are many orders of magnitude slower than the underlying computation - certainly you can prove that you took sufficient time to do the computation (e.g. using a VDF) or did it in few enough steps or according to some policy (e.g. using NARKS) but what is the point of using a modern GPU in the first place if you're going to be limited to speeds easily achievable by a 1990's CPU?
The only way this scheme becomes more useful than just banning GPU usage outright is if the proof of policy compliance can be generated only slightly slower than actually doing the computation. We don't have primitives that can do that currently.
There are some serious issues that need to be overcome for any scheme of this nature to be secure.
I think that from a quick read of the paper or from the summary in the post one might be led to believe that such a scheme could be implemented with a few years of engineering effort and the cooperation of chip manufacturers. In fact, substantial advances in cryptography would be required.
Policy-makers' attempts to enforce policy by requiring the use of special chips have in the past largely been broken: Clipper chip, DRM via SGX, etc.