This is bigger than most can imagine.

Hopefully someone with more tax knowledge than I will chime in, but as you can imagine, they are busy this time of year.  

Imagine what our grandparents paid for TVs relative to their income, for a 12" BW box inside a cabinet that weighed 300 pounds, especially in today dollars . .. . 

It's flawed in every way imaginable.

I can't speak to the other markets you listed but they are typically compared to our market here so I imagine they're similar.

You'll probably need 2-3 batches and multiple pours following the directions and setting time. 

Especially in vacation homes I imagine. 

If a significant portion of low income laborers were to be deported, both the cost and availability for pouring new concrete would become stressed.

Imagine buying a $7,500 roof every 6-8 years on your $50,000 house that collects $7,200/yr in rent.

I would imagine you're capped at 70% LTV to make the DSCR work at whatever threshold that lender allows (typically 1.00x) or maybe it's a credit/FICO issue. 3% in origination also doesn't seem too far off depending on the loan amount.