And he can purchase the property himself from the defaulting borrower, or purchase a (majority) ownership in the subject property.  

I have a question about how often I should follow up with a warm/hot lead.

There have been quite a few "hot-headed" investors who came through and were unsuccessful.

One more I can add is the note investor who thought that holding the note gave him the right to determine how the subject property was managed, with approval of tenants, leases, and maintenance contracts.  

I got opposing opinions on below and wanted to get what others know (or do) on the subject.

ARV can be somewhat subjective and lenders that uses an appraisal for hard money loans will defer to the appraisers opinion. 

Thanks, HELOCs the way you want them probably structured as a DSCR do not really exist to the best of my knowledge, you can do an investment loan heloc for a super high cost, but you will be subject to a traditional conventional underwrite.

However, Northern Utah seems to me an extremely hot market right now, with deals closing before they can even hit the MLS.

For DSCR, it's usually slightly higher than the conventional route due to it only looks how well the subject property rental performs + credit vs conventional where it requires credit, income, assets to be reviewed.

To what degree have you invested your time on this subject?