The increased frequency of these longer stays has brought with it increased issues.

Have you seen an increase on the rental side? 

We will create a unique website for each property which will increase its desirability.

But I can't see why Cleveland would increase in value based on negative population growth and, generally, being a bad place to live.   

The answer is clear: allowing full renovations without mandating sprinklers results in a far safer building than one that undergoes only superficial updates.Furthermore, requiring sprinklers in more buildings will likely increase costs even further.

Buyer preferences are shifting towards energy-efficient homes, smart home features, and open-concept designs, so incorporating these elements can increase appeal.

I considered starting out house hacking a MF, but it will only increase my monthly expenses, not lower them or provide cash flow. 

I do not understand your remark as related to the DSCR loan.  2 ADUs are not allowed by f/f conventional financing but is not always enforced.Fortunately if you stay with the current tenant without a refi, by the time you pay principle it is likely the rent will have increased enough to absorb the increase mortgage payment. 

By doing this, not only are you increasing the value hopefully building you some equity (giving you some boost in your net worth) but also increase rental potential too. 

My main aim of interest in real estate is to increase cash flow and overall build wealth that can replace my day job and give me more flexibility with my time.