Would we see increased cross-border transactions and a surge in property investment opportunities?

The 4% isn't much, but it's better than nothing and it means my security deposits increases with rent each year. 

Also, the tax benefits of the buy and holds help offset the increased tax consequences of fix and flips.

However, I enjoy the more operational side of flips and would like to grow my business out of state to increase flipping volume and have less competition in finding deals.

Your equity won't likely increase beyond the cost to build because there aren't a ton of ADU comps on the market yet. 

They may also require US credit history, although there are a handful that will not require a US credit report for an increased rate/ reduction in LTV. 

We plan to remove them all to protect from tax increases on our current primary, but I am afraid that now that the other properties won't have homesteads, we may see skyrocketing tax bills and it will eat into already small cash flow from rental income.Does anyone have advice for how to handle this situation other than just increasing rent?

I will mention that a hot tub could really increase the frequency of bookings. 

The property was leased for $2,150 per month.Refinance and Return on InvestmentAfter a stabilization period of 6 months, the property was refinanced to leverage the increased value created through renovations.

Pretty much the core of the STR business.Higher your rank gets, you can increase your price and be more picky in selecting customers which usually lead to a better review / less party or complaints / less expense and higher profit with a happy life.I know some people will argue, but the ranking system is the truth and should be the only guide to your STR journey.