Six figure income is still impressive for any residential SFR..optimally rates improve and so will rates of return with a refinance.

@Nick Am Setting up a management S-Corp (LLC-B) to manage properties owned by your LLC (LLC-A) can provide tax benefits like retirement contributions, payroll tax optimization, and deductible expenses (e.g., home office, health insurance).

Focus on optimizing the current fourplexes (improving rents, reducing expenses).

Does this matter if you're not optimizing for building a ton of wealth to pass onto kids? 

I am also looking for tax optimization as the business will require cash reserves and is a high risk business from a liability perspective.

Before committing to paying off the property, analyze whether there are ways to optimize revenue, such as better marketing, adjusting pricing, or upgrading the property to attract higher-end guests.Return on Capital: If you pay off the mortgage, the “return” is essentially the 7% interest you’re saving.

A real estate tax pro  can help optimize deductions, ensure compliance, and avoid costly mistakes most importantly so that would be the next step 

Even with the discount, the investor will be a life style investor who wants to own in PR more than optimize return.  

Zillow spends million upon millions of dollars every year on SEO and marketing.

Just my opinion but I think 2 years is too soon to consider exiting deals (minimal appreciation and less than optimal use of depreciation).