Adds a configurable equipment grid to any base or modded vehicle without grid.
Mods introducing new content into the game.
Armors or armor equipment.
I'm playing with the helicopter mod, and it loses its grid when you pick it up. Items vanish, not dumped to inventory like fuel and ammo. Other vehicles seem to remember and maintain the items in their grid just fine.
Not a bug with ReStack.
Sounds like Helikopter uses the wrong prototype. https://wiki.factorio.com/Prototype/ItemWithEntityData