Yes,
and put a different way, you can say to such passengers:
"If I have the information to accurately calculate the total aircraft weight, I can fly it the way it was designed. Other than that, it's a test flight, and I cannot assure safety. Would you like to go on a test flight, or shall we fly it safely, the way it was designed?"
This theme also works well for passesngers who are unwilling to wait for last minute maintenance to be completed.
Pilot DAR