You would be surprised at who buys pallets and pallets of this fuel
If the sanction bodies are going to try to regulate fuel it will have to be some kind of fair Go, No-go method, using a dielectric meter and, or a spectrograph otherwise it’s the wild Wild West.
When they start, then people that have had years of experience in pumping fuel, then developing masking agents to cover their tracks will have a field day with diesel fuel.
So unless you’re willing to start that ball rolling, it’s all legal