The specialist I recommend you have is an attorney to properly draft the documents and a title company to facilitate the deal.

Thanks,James The only reason you could not keep the HELOC open is if there is something in your original loan documents saying the loan would close once it was not your primary home anymore.

When I asked for identification documents, he claimed it was too many documents for an investment of "only" $10,000.

but working with someone who is local to your market, who can show you their legal documents that they have used, introduce you to a proper title/attorney office for drafting documents...I mean, nothing is foolproof...but that route will have a significantly higher success rate. 

There’s a good chance that if lender finds out of property transfer via title records, insurance policy beneficiary, bank account submitting mortgage payments, they’ll assume that John  Smith formed a trust to own title and will not flag the  file for any action.  

We submitted an offer while away and all via zoom.

In the future, please have all this lined up before you submit a contract.

https://www.biggerpockets.com/...12 Frequently Asked Questions (And Answers) About DSCR Loanshttps://www.biggerpockets.com/...8 More Commonly Asked Questions and Answers to DSCR Loanshttps://www.biggerpockets.com/blog/eight-questions-and-answe...What Documents Do You Need for a DSCR Loan?

Document everything. 

You don't have to file "Trust" documents in order to hold a tenant security deposit in trust.