However if I do this I know this tenant will bad mouth me more frequently to the other tenants in the building.

Im in your part of Florida frequently.

The two most frequently used companies for this service are KBKG and DIYcostseg. 

https://www.biggerpockets.com/...12 Frequently Asked Questions (And Answers) About DSCR Loanshttps://www.biggerpockets.com/...8 More Commonly Asked Questions and Answers to DSCR Loanshttps://www.biggerpockets.com/blog/eight-questions-and-answe...What Documents Do You Need for a DSCR Loan?

I had to ask questions to get explanations about frequent repairs.

I am American, but I moved outside the states a couple years ago, but I expect to start spending more time back in the PNW in the the next few years, and a stretch goal is to be able to accommodate friends and family when they visit, which should be increasingly frequent.

Every system you try will have flaws, or you may salivate over a feature that appears in other software.Some familiar names are mentioned frequently: Stessa, Apartments.com, RentRedi, TenantCloud, Innago, RentManager, Avail, Rentec Direct, Doorloop, etc.I recommend conducting thorough research on each app online to understand their offerings, pricing, etc.

I seek zoning variances frequently in Philadelphia, but its a lengthy process and don't personally find it a worthwhile pursuit for legalizing a second unit in a building.

Can you bring your portfolio closer to save on frequent flights to maintain better control/save time?

I don't invest in multi-family properties myself but one of the Bigger Pockets frequent contributors on these threads is Brian Burke, who quite literally wrote the book on this, I am buying a copy myself, but please read, i think an ebook available too, I do passive investing only in multi-tenant triple net retail but have spent hundreds of hours doing my own due diligence.