Because the condo price is so low, I would still have a decent monthly savings rate towards my next deal.I’ve done a lot of research on duplex house hacking but almost none on condos, so I’m unsure how big of a deal things like HOA reserves, rental restrictions, special assessments, or resale value are.

Not enough data to do anything but blindly guess:(What were the previous special assessments for?

Has anyone come to a definitive assessment of the legality of rent-by-the-room in single-family residential zones around Atlanta, Georgia?

As Greg said, if the HML says no after they assess the deal, you need to ask yourself why? 

I work very closely with Wander in the PNW and have sold properties they pre-qualify and manage for clients and assessed STRs they actively managed that came up for sale. 

HOA's scare me a little with the assessment fees and all the possible surprises.  

You will want to find out if it is warrantable and if there are any large assessments coming up that you would be responsible for. 

To more fully assess the situation, it'd be helpful to have the numbers in front of us with cash flow potential

Find a handyman or home inspector to go out and assess the condition and have them write up what they see needs to be do.

To make informed assumptions, it is essential to assess the expected rent growth for similar properties in the market over the next few years.