Hello !
Unless I'm doing it wrong, it looks like the locks aren't working as intended on my side.
I'm using the Dunes graph comming with the demo. I'm pinning 4 tiles across the world. I'm making hand made height modification (flatening) to those pinned tiles with the unity tool. I'm locking each modified area with the lock tool. I'm running playmode.
The locked areas won't retain the hand made modifications in play mode. Generation will apparently ignore locks unless the pinned/locked tile is in the range of the camera or any tagged object used as terrain marker when launching playmode. Even so, if I then move the camera away (or untag the markers) so the tile unload and come back to it so it regenerates, the lock won't apply anymore.
Looks really weird, and I'm pretty sure I've experienced locks working just fine when I've first tried it a few days ago o_O
I'm using Unity 2019.4.16f1 and MapMagic 2 Bundle 2.0.8
Edit: I can reproduce this in any empty scene containing a MapMagicObject with a Dune graph and using a single pin/lock.