I think Missouri Ag claimed there is no valid 303 spec to compare these products against. Real 303 contained whale oil which is a superior lubricant but today anything containing it would be illegal to sell.
So conformance with the retired 303 spec is legally impossible and their assertions can't be true. I think Missouri Ag further claimed various brands of 303 aren't the same product, depending on vendor. And some vendors of 303 claim it is suitable for nearly every tractor, a lie that could lead to expensive damage.
So in the absence of any standard to compare present '303' against, they banned it in that state to protect their consumers.
I run the stuff in my simple manual-transmission YM240 and in my backhoe. I think anything roughly similar to UTF is sufficient for these. For harder commercial service, I would probably step up to modern name brand lubricants.
For the PowerShift YM186D I think uniform viscosity and proper detergent additives are more important to keep the hydraulic valve bodies and clutches in good condition so I use J20C-conforming Traveller Premium. Still a cheapskate choice, but I think that is sufficient.
