It would be a good idea to assess your tolerance to risk and then plan something like that, but using a heloc is going to be around 9-11% in this market so to pay something off with lower interest rate to borrow more might not make much sense.

What market?

This clearly has nothing to do with laws, regulations or operating numbers but I do think it plays a large role in the decline of the market.

As someone who occasionally works with these investors, I always try to emphasize the challenges that come with real estate like managing renovations, dealing with tenants, and navigating market fluctuations.

I believe that is safe to say for most markets in the US regarding either SFH or MF.

There are many factors, as with any real estate market:(1) Location. 

What are the benefits of SUB 2 financing a property?

However; the real estate market here hasn't stopped at all, and it's blazing.

My only tip is to stay on top of the market rents in your area.

We are not familiar with any of these markets, nor do we have anyone trustworthy there, or a real estate agent.Our approach would be both rental and house flipping.