I like the Canada and very similar U.K. Systems. I note also that neither Transport Canada nor the MCA are military organizations, anything like the USCG. The US would be smart to move toward a similar STCW compliant system with only one type of license tonnage.
Interestingly, the U.K. MCA will not simply issue a CeC for a US limited license, only Unlimited US licenses.
The holder of a USCG Master 1600 GRT oceans, and STCW II/2 - 3000 GT license must take the UKLap exam and the U.K. MCA Master’s orals exam in order to get a U.K. CeC.
I did not look for or see any indication of how the MCA treats USCG OSV restricted licenses. Does the MCA recognize OSV licenses ar all?