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Anyway,
some 2015 new Garmin devices don't accept unlocked maps, they have a protected firmware looking for digital signature in map, and .gma.
If digital sig. and .gma are missing map doesn't work, I guess on new IOS can be the same.
But you can try because in all other previous devices gimgunlock+mapsigpatch works, unlocking and patching digital signature in map. No .gma and .unl needed (remove them if present).