that’s surprising.. i don’t undertand what is the reason that lies behind this HO. A MS in AMR FR will use the same amount of resources than if it were in Legacy FR.
are you sure that these thresholds are not to go from AMR FR -> AMR HR, or AMR HR -> AMR FR ?
if you’re sure, then i don’t have an answer for you, you got to check it out with your vendor(s).