My options are A) accept the stability and lesser headache that comes with taking no action for the time being in exchange for accepting his below-market rent, or B) accept a turnover from a good tenant and pay for a renovation in exchange for a significant rent increase (in the ballpark of +15% right now with a strong upward trend).My inclination is to go with option A and renovate when the tenant chooses to leave or when the disparity between what he pays and what the market rate is gets closer to 25%.

I'm assuming this is not a secret bank and they have an online presence where their address is listed and is easy to locate. 

For buyer's that are financing, having a strong pre-approval and a lender that is capable of closing quickly is important too. 

Both are in relatively strong rental markets (Los Angeles, Tucson).

Fortunately my credit was strong enough to weather the storm and I was still able to refinance the BRRRR property.

They have a strong student rental market, affordable prices, and I assume will be within driving distance of where you live.

It would be advantageous to run the numbers and see if it's better to leave that unit vacant or if your return would be greater by establishing a strong rent prior to the sale, as well as what the best strategy is for the new capital, which I'd be happy to go through with you. 

Looking for some insight from experienced STR's about whether or not guests would be turned off by the presence of exterior security cameras (definitely nothing inside the house - except inside the garage which likely would not be accessible to renters - debating that). 

I think it is a really strong metro area, happy to share my analysis of the city if you want to share your email. 

It's great that you guys have a strong investment partnership going, so hope it pans out well for you both.