@Maya S.In representing both lenders and borrowers, I’ve seen some solutions other than tenant signing an extension prior to closing.

I have a signed contract.

If you sign up as a client they provide legally vetted forms and can advise on the process at no charge.

Do I need to have them sign a new lease with my company name on it not changing any of the terms or do I just inform them on how to pay the rent? 

These sellers hand you the keys and stay out of the way until its time to sign a contract. 

DSCR will not work as they are business-purpose loans and you will have to sign an affidavit of commercial use. 

I find little reason to pay for a service when it takes so little time for us to simply split the water bill as agreed when the tenant signed the lease.  

Some have signed 2025 leases already.

A certified letter is good because they sign for it, acknowledging receipt, any other forms of written communication you can get to document that they were notified of the hazard probably also helps. 

Offer accepted, "My I have an email to send you a purchase and sale agreement via Adobe Sign" Offer rejected, put in the follow up bin.