Long story short, the properties were far from turn-key and required that I find an out-of-state contractor and property manager to complete renovations and find new tenants. 

I suspect maximizing the investment might make it slightly less desirable as an owner or at least the renovations might have lower ROI if sold to a homeowner.

So what if the heloc amount is enough to cover 20% down on investment property and cover renovations.

I personally do have experience with renovations, and being a landlord and have done a few flips some went well and some did not and I have learned some valuable lessons along the way.

I have found some information that might be helpful John.There are government backed programs like Fannie Mae Homestyle Renovation Loan and Freddie Mac Home Possible Renovation Loan, in addition to the FHA 203k loan. 

They used a HELOC to finance a multi-family purchase, which allowed them to make staggered acquisitions and keep cash on hand for renovations.

Renovating dilapidated homes is one of the ways to make money in real estate.

These professionals often look for properties like yours to renovate and flip or hold as rentals.

Easier to do with a duplex year by year, but when I rented to students I would quickly renovate for winter break. 

I can add value to RE by adding a bathroom, renovating the kitchen, ADU, etc.