Then I started thinking, perhaps I could acquire a turnkey 2b1b and do an addition to force appreciation and refi on the backend with a larger 3b2b and still effectively BRRRR and have a new rental in my portfolio.

Many on here will disagree with me, but owning scattered site single family portfolios is an effective investment strategy is there is a a significant appreciation event that occurs.

If you are working your local market, there are other methods of finding leads that are more effective than cards or letters . . . see what is working in your area from REIG members.

Just to add my two cents, I think the most important aspect to be a successful investor, in any market, is to have an excellent team in place that will help cut your learning curve significantly, help you to quickly identify the prime areas to invest in that market and manage your properties effectively!  

If you're looking to build before EHB 1337 takes effect, check out this spreadsheet to identify which jurisdictions are friendly.

A lot of people don’t realize this, but in addition to real estate agents selling stuff, they are also being sold, every brokerage, every title company, even lenders, have courses on literally scripts, how to build out your social media, how to find fsbo listings etc, truth is none of these are effective, pretty much the only way to be a successful agent is either ton of ad spend or the hard work of meeting people in person through events meetups etc, but brokerages make money by head count, even title and lenders are happy if you close a few deals a year with them, so they sell this stuff to agents who than use those scripts on you, it’s a whole prymond scheme lol

I think handwriting these letters will be much more effective than just a typed-out print.  

It can be very gut wrenching/teeth pulling but it's very effective if you consistently do it.

And working on the foreclosure side of a bank, I can't tell you how many folks I've seen have one or two rental properties fail, which created a domino effect that completely wiped them out.  

This has the same effect as doing a partial exchange and paying off one property.