They are two entirely different problems with different solutions:
(i) Patching MapInstall and BaseCamp simply allows you to unlock PC installed map data with JM and also send map img files to any drive, not just devices and media cards.
(ii) Patching modern protected device firmware allows use of unofficial/unlocked maps when with original firmware they would be unusable and the device would report on boot "Can't authenicate maps/Maps are corrupt", or similar message on screen.

Be aware that there is a problem using patched fw on Montana 680t, to workaround it after loading patched firmware you must reset the unit and disable Geocache Dashboard in map settings. If you don't do so before using an unlocked map the unit will lock up when the unlocked map's selected.