Using Romex clamps like that is always wrong. Why not just take some bare solid #10 and wrap and twist it around the conductors? At least it is not likely to damage the conductors nor to break.
And the point about not mixing Cu/Al is quite valid. But if you apply anti-oxidant and wrap it with rubber tape, then it should survive "temporarily".
I think it is so much easier to just use the right split bolt. I'd hate to have the clamp on the neutral break while my tools are powered from the temp service.
