Signed message will be provided if a lender is confirmed.
If you sign a message that will make any guarantee of the repayment of the loan that you will take and/or which has already defaulted? If not then there is not necessary about the sign message.
The only thing that can bypass any concern is offering collateral
No, no, bro! You can't say only one option. There is another option and that is repay previous loans which has been scammed by his/her alt account/accounts.