This was in fall of 2018 so the rules may have changed AND I ended up using a conventional loan so that I wouldn't have mortgage insurance for the life of the loan. 

That is a conventional product that has better terms than FHA.

conventional Lessons learned?

I got a conventional loan (3.5%-5% down) and rented out my empty rooms to some of my friends.

Just closed on a primary home today & now am wondering the best way of handling the home I'm in.Would refinancing be worth it if my interest rate right now on a conventional is 4.75%?

I'm able to do 80% LTV on the ARV per the appraiser, pay interest only for 12 mo and then roll it to a conventional mortgage when the rehab is complete.

One thought I had was to perhaps put together a direct mail campaign to try and source deals, but my hesitation is that I am currently working with a conventional lender and do not have money on hand for cash deals which I feel are more typical in off market transactions. 

Might consider rolling into a conventional to free up your VA.

So I'll base my opinion off your numbers.120k ARV using new LTV 65% for a standard as I have heard some lenders moving to 65%, so it is $78k for refinance.Loan on $78k @ 3.5% APR is ~$650 PITI for 30 years conventional, also used rather high insurance numbers here for a conservative estimate.You paid $19k cash with ~$35k rehab for ~$54k in total costs.Refinance of 78k - 54k cost = 24k cash out at refinance. 

I have conventional loans on my properties so that I can have leverage.