That's the way, thanks.
I realise what sub-forum I'm in and have no experience with the MP, but I take it this one doesn't have the smart battery interface of the newer equipment?
And if that's the case, assuming the MP has a 4S battery, the only concern is that the HV batteries are 0.15v higher at full charge, per cell, than regular LIPO batteries. Thus, for a 4s battery, your drone would be expecting 16.8v max while the HV will deliver 17.4v. Most electronic components have between 5% and 15% headroom for overvoltage, but not always. The esc and motors especially would probably be fine but the camera and flight controller may have at least hotter mosfets and at worst, something failing from heat.
Do you know if it's been done before? My money is on it probably working, but be aware you have a flying computer and camera rather than just a bunch of motors and ESCs, which can typically take the extra heat.... Typically!