If you're using a HELOC, I assume this will be based on the value of your primary residence.

Nothing more needs to be done.Some MLS systems require the signed withdrawal or you can get fined as an agent.The MLS where he is talking about has zero power over this.He is using a form of the association of which Im the President-Elect.

Thank you yes that make sense, inclining towards using a combination of free sites and select one paid site like FF, in fact I am looking similar to you for 3 months minimum stay and yes, rooms are furnished.

Using a HELOC can work, but it's still a second loan on one property so I wouldn't be looking for a way to leverage one of your two properties just yet to get a third.

Using a VA loan as a financing method for the house hacking strategy is great way to build equity.

Sell the home take you share and buy an investment home using a DSCR loan you do not need income or a job with DSCR.

Could I fund the purchase using a bridge loan with the assumption to sell my existing home ($1.5M)? 

If you are going to be active, and have high conviction in a project with a clearly defined entry/exit strategy then using a HELOC is one of the better sources of capital.But, I continue to have my stance that, on average, folks who use a HELOC to fund the down payment for long-term investments will eventually find themselves in a situation where their portfolios drain their personal financial situations, rather than fueling them. 

We financed this deal using a conventional loan, and taking portions of my 401K out to make the down payment and stage the house for STR and MTR.

I suggest you look for clarity on what resources you can use or companies can assist in using a small piece of that equity as a downpayment on another high-quality asset like the one you already own.