To allow for clipping engines inside of a mount or the part above when no mount is present.

Requirements:

Add variables (temp and persistent) to handle the offset
Add handling to engine model-position update code
Add on-editor-changed code branch for height offset
Add handling of offset position to fairing and node update methods

just press 2?

This would do it mostly to offset the engine into its own integrated mount, and or offset it into other parts -while not clipping the fairing or mount model.

Mostly this function will be useful with the upcoming 'shroud' series of mounts (and is in fact the main feature that will make those mounts usable with different engines).