Let me give you an example from the Canada-Panama FTA that was just signed. The FTA was not germane to how Panama deals with MRLs, but they have an MRL deferral path that essentially says that their MRL is going to be the Codex MRL, but if Codex doesn't have an MRL in place, it's going to be the U.S. MRL, but if neither Codex nor the U.S. has an MRL in place, then they are going to defer to the EU MRL.
There are many precedents in sovereign countries for the interim solution we're asking for, namely, some form of mutual recognition of MRLs. You can take the MRL off a shelf from the regulatory system of a country you trust and accept it as your own on an interim basis until there is some improved degree of regulatory harmonization. There are examples of this out there.