When my wife and I started out we new we wanted to invest but did not know how to, we took action and unfortunately found a family friend realtor (amazing learning experience) then we found bigger pockets. 

Also, I am assuming since you house hacked that you only did 5% down, which then increases your mortgage payments compared to 25% down buyers.

And then shut them down.

Quote from @Mario MoralesMorales: what if he got a HELOC, used the funds to get a property, then cashout-refi the new property and pay off the heloc?

Plus,  if you have the ability to do another FHA 203k, it's a no-brainer.The low down payment is unbeatable, and then add on that the bank will all finance the renovation!  

But if you want to maximize your deductions now or plan to sell the property soon, then using it now could be better.Also, if you or your spouse qualify as a Real Estate Professional for tax purposes, the losses could offset other income, like your W-2 salary.

Since then, I have sold all my active investments except 1.  

The reality is the opposite - if it's not in writing then the PMC doesn't have to provide the service or can charge extra for it!

If you are talking about 2-4 units, then it's really no different in my opinion.

If your willing to do so, you can live in the casita and then rent out the main home and have your tenant pay the majority/all of the mortgage (depending on what type of deal you find obviously).