Welll, it boils down to the propane recommendations in the National Fire Safety Assn propane manual, which individual states are free to adopt or to modify. For example, NFSA says to fill DOT bottles as on RVs either by weight (a scale) or by volume (using the bleed valve), but NM wants fillers to use weight unless volume is necessary. (It's an environmental thing: Filling by volume always shoots a certain amount of propane into the air.) Noteworthy is that the NFSA does not mention or suggest using the OPD valve as a means of filling.
But, again, the NFSA manual is a set of recommendations. It's possible that some state someplace could permit filling with the OPD valve. (And it's also true that a number of fillers in states that disallow using the OPD do so anyway.) Personally, I wouldn't: It's like trusting a mechanical device that sometimes fails with somebody else's well-being. Ultimately, if a filler illegally uses the OPD to fill, overfills a bottle, and an accident results, the filler could (and should) be held responsible.