Where are you looking for availability? Only DVC members have access to the DVC rooms that can be booked on points. The rooms you see on the Disney site for cash reservations is a different set of inventory.
I used a couple of tools that were available from DVC Rental sites for current availability. And I used DVC info for overall room availability.
We are planning our 2020 trip with the in-laws (getting 2 poly rooms for 8 nights) and already planning a 2021 trip because we will get AP's. So much for renting them out to make money.
Sounds like you're considering everything. I tend to play a little devils advocate in these threads. Good Luck.
I've considered this too!! I looked at some Grand Villa costs and decided...I'm nice, but not that nice.

But in the scheme of calculations, if we're going; we'd be using it. And if we didn't have it, we'd be renting either DVC or hotel. I wouldn't be hurt about losing out on the rental money as long as we're using it.
You could theoretically get 2 studios at Poly for your family...pretty good chance you get connected rooms -- but at a minimum, you'll at least get rooms that are pretty close together.
Also -- poly studios have two showers and two sinks, so that is very helpful if you're trying to squeeze everyone into just one room. VGF is the same (2 showers and sink areas).
The problem with getting 2 studios at Poly is that it's expensive. The points for 2 studios would be more expensive than a Lake view 1BR at BLT. Having 2 bathrooms in the suite (and being a large one) does help though as we could potentially just have a studio alone. 2 Bathrooms has been key for us right now.
I personally wouldn't get too hung up on what is the best overall value. If you love a particular resort a lot more than another -- then the happiness you'll get from being able to routinely stay there is probably worth the extra money you'll pay to get the home resort priority. Not to mention -- if your plan is to rent the points out -- you'll be able to charge more for renting BCV/VGF/BWV points compared to SSR/OKW.
AKV is a fantastic resort -- but the walk to your room from the lobby (at Kidani) could end up being VERY far. Not to mention -- bus access to everywhere.
If you have children in strollers -- I would highly recommend staying at a monorail resort or a resort you can walk to the parks (e.g., BWV/BCV). Dealing with the strollers on the buses with sleeping kids at the end of the night is not something I ever want to repeat.
I think they're fair comments. But the reality is if we can't at least breakeven, it's hard to justify for us to do this. That's mostly because we really don't have any issues with AoA right now. We're quite happy there with the location, transportation (even w/o a running gondola). Ignorance is bliss and we don't know what we're missing...
If you have children in strollers -- I would highly recommend staying at a monorail resort or a resort you can walk to the parks (e.g., BWV/BCV). Dealing with the strollers on the buses with sleeping kids at the end of the night is not something I ever want to repeat.
...until you brought this up. Now I have to consider Poly... But in all fairness, I don't think there's a magic bullet. We're a 4 park family. So at some point I will have to deal with a stroller, sleeping kids, and a bus. I think the only way to avoid doing that is if I went through a park. (ie, Walk from HWS to Epcot to take the monorail) and even then I think a bus is the only option at Animal Kingdom.