Personally I'd use it as a DP for a hard money loan on a flip or BRRR.

Keep in mind HELOCs are interest only payments, adjustable rates, and will eventually turn into a fully amortized loan (usually after 3-10 years).Cash Out Refinances are great when you need the cash for long term needs or consolidating debt.

These are mostly 6-month interest-only loans with 2 points up paid at closing.   

What should I know about using FHA loans for out of state investing?  

Would a 203k loan work in this situation or do I have to apply for a personal loan? 

A lot of investors use DSCR loans to acquire multifamily.

He has a 3.5% assumable loan in place, but it only has 20 months of term left.  

A lot of people left, they let their bank have their house that they had a loan for.I buy the bank foreclosures, furnish them from estate sales, then rent them out to the contractors.6 months of STR rent pays for the purchase price of the house. 

They were slow with their loan reinstatement letters.

I am also a licensed realtor, have worked a loan originator for hard money lender, have light general contracting experience.