Is there a trigger for when a lead gets converted to a customer? i.e. If someone loads a lead then creates a Sales Order, that lead is converted to a customer. But I can't find a way to have a script run on the lead/customer record when this happens

I think you'd have to run the script on the Sales Order and check the Customer's status via a load or lookup - I'd guess that in

beforeSubmit

, it would still be Lead/Prospect. I haven't actually done that myself though so that's just a guess.

Thanks, I think this would be a sufficient workaround.