Seeing as our house is pretty rural, our choices are limited.

Totally new world for me knowing there are properties off the market, wholesalers, and people that loan money just for this purpose, different from a bank, I have always thought we were doomed from finding a good deal as everything I found was already on the market...my little knowledge and limited believes got me trapped.

I saw two recent studies comparing rental costs to home ownership.  

Also, not looking for feedback about the value/necessity/negatives/ or need of doing a study.

Most will likely stick to the technical limit of Sept 2021 when it ceased being a primary residence, but some may be comfortable going by the address on the 2021 return and others may explore a partial exclusion, depending on the reasons for your move abroad.If you'd like to read up on the technical rules, the IRS publication 523 gets into more detail than most people would like to know, but it does have some helpful tables and examples for different scenarios.

If you stop growing it wide early (more real estate) and you start growing it deep instead (more equity) you are limited in your final outcome.

If you are convinced this is the guru you want to follow, pick up a cheap resale on amazon or ebay...read and study it cover to cover. 

Most people that have limited experience go the thought leadership route.Start learning everything you can about real estate investing and then regurgitate it by writing blogs, starting or being featured on podcasts, blab about it on YouTube and social media.  

Also keep in mind that with HELOCs there are loan to value limitations.

The reason is that we have a relationship with a regional bank that will provide financing and which if we limit leverage to 50% will (1) charge interest at their lowest commercial rate fixed for 20 years with no balloon, (2) charge 0 origination points and no “junk” fees and(3) allow us to sell the property with either a sub to or a wrap loan without increasing the interest rate - in other words no due on sale clause.