Stockpile the savings.

My ex-employer in recent years stock piled SW engineers for future work that we did not even have yet. 

With that amount, you could handle multiple repairs on several properties at once while continuing to stockpile cash. 

However, deployments provide a great opportunity to stock pile cash for downpayments once you return stateside.In short, I don't see how being deployed should hamper your investing and managing activities.

I will continue to leverage until we feel we've had enough, and then focus on stock piling cash for alternative investments.  

If, however it truly gets out of hand to a point of creating a fire hazard or impeding the ability to make a reasonably hasty exit; or if they are completely blocking an exit or an electrical panel; or excessively stockpiling recyclables or flammable material; if food has been clearly left out for extended periods, with roaches crawling all over it or worse, and household rubbish is not being reasonably contained, I will give them ONE 30 day period to make dramatic improvement, a second violation would result in non-renewal or termination for cause.

We have no debt, and a large cash savings stock-pilled (around $2M).

Should I pay off the HELOC as fast as possible or stock pile cash?

C) Wait until March 2021 (1 year after purchasing #2), continue collecting rent, stockpiling money for emergencies, and do another HELOC on the equity in #2? 

Cash ain't trash...a lot of big investors are building stockpiles.