Seems to be a lot of concern about MRID modules.
Just can't see adding such a module that requires an external battery! A coherent and cogent approach to obtain power from the Drones shouldn't be that difficult!
There are a number of small commercially available power modules with the ability to take in 20VDC to 30VDC have been on the market for decades. The output voltage is a variable adjustment on it.
Search for LM2596, (if memory serves), can be obtained directly off of E-Bay.
I already have these, and have used them to power VCXO Modules.