If you're using it to just buy additional property using a BRRRR method, then you would draw down the credit line and pay it back fairly quickly and get yourself back to strong cash flow again.

I’ve been learning how to deal with seller objections, trying different marketing methods, setting appointments, estimating repairs and formulating an offer, and learning more about the indianapolis market.

And inspect their house for water leaks in plumbing.

It is the method to tap into your equity without selling that is the powerful part.  

I do only rental rehabs taking a 1975+ split level 3/2 and just causemetic;  paint, fixtures, flooring, new HVAC, rarely a roof, never windows,  paint the kitchen cabinets with new hardware, clean up baths, just clean up landscaping, fix things beyond replacing all ceiling and plumbing fixtures (except shower valves) and this has grown to $25k is now tight

Interested in the BRRRR method.

Oftentimes, landlords want to sell when the big items start needing to be replaced, roofs, HVAC, sewage lines, electrical/plumbing etc. 

The simplest starting method for a person with little starting capital, from my perspective here in San Diego, is to utilize a 3.5% down FHA loan (and/or VA, if you have it), seek out properties that are slightly under market rent, give termination of tenancy to the unit with the biggest delta of rent vs. leading rent in the neighborhood, move into that unit while you renovate it, and then rent the unit at leading market rent a year or so when you move out.

Then I'll transition to the BRRR method, though I'm not sure if my focus will be single family or multi-family.

If I use the method for depreciation found in that article you linked (also pasted below), my deduction for that will be larger than the principle payments for the first 21 years of the mortgage!