I think the 2 biggest hurdles are finding the right team to do the work, given you won't be there to monitor it 1st hand.

They can bring payments to the office or send by mail, but anything mailed is not considered paid until it's in my hands.

Im an investor and agent in Phoenix who's helped a handful of folks with 1031 transactions.

I'm not completely foreign to the construction process as I grew up around a family that was involved in home building, but due to living in another state I can't really lean on them for the direct, hands-on guidance. 

I also own properties in C/C+ neighborhoods, and although the cash flow is higher, those properties are more hands-on, and I typically experience higher turnover.

Just make sure and do you due diligence before hand. 

Instead of having multiple SFH or duplexes that would potentially require a more hands on approach?

In my experience, success in D-class areas almost always requires being local, extremely hands-on, and self-managing.

I've largely stayed away from the "sub-to" buz word, but I have done a couple sub-to flips knowing that I only needed to hold onto them a couple months and I was prepared to pay off the notes if they were called.Sub-to for long-term hold on the other hand has me nervous. 

Investors on the other hand are often over extended and can not make timely payments.