You can use different files for submission and actual sales.
It is allowed to make necessary modifications to fit into the space limits such as size, polygon count and number of materials.
However, please cleary notify that there is discrepancy between the exhibit and actually sold product in the product explanation or the store page.
FAQ
My item is too large to fit into the space. Can I submit different data from what I’m going to sell such as shrinking the model?
You may modify your submission data such as the size if needed.