I spent most of my adult life deployed, living out of a bag in third world sh@tholes.

In the last couple years, mostly outside residential real estate where investment tax credits still exist and 100% depreciation can, tax wise, return about the full capital account within the first year of capital deployment. 

IMHO, the biggest thing holding owners back on deploying more AirB&B is the time needed to answer inquiries..

Additionally, we need to decide whether to continue with higher end flips or deploy the proceeds in to buy and holds in different markets. 

That money that you are saving each month could be deployed to purchase other properties rather than helping to pay off any specific loan.

Will the expected appreciation give you the return on the existing equity that is attractive to you or can you deploy that $510K somewhere else and get a better return?

Of course, there are always exceptions to the rules---for example, if you can get a greater return on your investment by deploying the equity elsewhere or if the cash out refinance will be dedicated to improvements/efficiencies meant to improve cash flow---these are just two circumstances were your thought process could make sense.

I was recently stationed in Japan while active duty and throughout my last deployment I committed myself to listening and reading as much as I can on self development, long distance real estate, healthy marriage, and overall life success achievement.

Freedom from punching a clock or being deployed. 

In Colorado Springs, for instance, the law requires that any vacation rental (excepting for a few pockets here and there) be your primary residence, but they do have a limited exception for military members deploying overseas.