-We have debt pay down, as our tenants progress through the mortgage-We have tax benefits that enable us to trade up or simply claim deductions.What refinancing does for YOU is allows you to catch those profit centers.  

I have not done a 1031 exchange, but my understanding is that often times people do that to "trade up" to a larger (or bigger) asset.

Is a paid off primary a desired outcome or just a debate?  

There are trade-offs for each city, so you need to better define your goals.

What was the outcome?

@Jerry Zhang - What do units normally trade for in the area?

I work in the trades as an electrician.

Light renovations What was the outcome?

A Heloc is a open end mortgage like a credit card so its an additional trade line on credit, cannto never be used as an Asset, PITI reserve, and its a DTI killer in most cases.A heloc is also usually set up on a shorter term versus a mortgage, carries a Higher interest rate, and most carry a interest only with a prepayment penalty.

Soft assets like specific stocks and preservation phys assets this may not apply to, but you keep those at low % in your portfolio and actively "trade" those.