"When you say create a bounding box and delete the bounding box, do you mean that you want an actual separate box object to be created so that there's a big extra box geometry additionally inserted into your export?"

No

"Or are you just talking about creating a bounding box only as an internal calculation step (not actually creating any box geometry to export) for getting the base point?"

Exactly :)

"If I understand you correctly you want the entire selection to move more all together keeping the pieces in the same relative position and not move each one separately to the origin"

Spot on :D