you don’t actually have to use the “merge” function, you can just navigate to where you saved the scene subset and load it like any other figure/prop in the content manager
I’m doing a bunch of vehicle conversions and found that the only way to save everything properly is to use scene subset (multiple objects parented to a main obj then setting origins & limits on certain rotations for wheels, doors, etc.)
BTW, you can also use the merge function to merge a saved scene with a new one, but you will probably need to delete the parts you don’t want in the new one.