At least make m 1:1 scale, to provide yourcustomers with an acturate starting-point > if they want to change that to something not-realistic, then they can do that themselves.
Seems obvious to me, actually.
Gems/ additions: Probably obvious again: Either supply them in separate file (same scale/ same position) or make sure they're part of the main model > no space between the walls: ie. gems need to be wall-less and integrated in the main structure.
And as an option, deliver 1 file without gems and one with gems (properly) integrated; WHo knows, maybe they DO want them in there and just paint them.
Anyway: I'm all for being as prescient as possible.
Hope this helps.