I've been to Snake Cay once and can offer some (mostly useless) pointers. It's accessible by land which makes it easy to get to. It's pretty deep, making it best to access on low tide. It's not very shielded from the Atlantic, so there will be a large variety of fish around, much more so than a traditional flat detached from the open seas. The north channel is a favorite of divers, the tidal currents are quite concentrated here so it's an excellent area for blind fishing from a boat.
I was there on an overcast day, and that made it tough to spot the bones. They were there, but in 3 feet of water, it's almost impossible for an amateur to spot them before they spot you without the help of the sun. We waited for low tide, and that made the job a little easier, the bottom varies nicely in vegetation and depth, and we even found a school of 10 tailers feeding on a shallow spot, at least until I spooked them to hell of course.
I would not be surprised to see this area regularly visisted by trophy bones with deeper water so close.
So for spotting fish, and especially if overcast, match up your visit with low tide if you're on foot. Of course low tide might not be ideal for when the fish will feed/enter/exit, but it was deep enough for us to constantly have to detour and deviate from our path when wading it southwards even on low tide (relatively). We only covered about 1/2 of the area (North-most), before we ran out of daylight. I'd be happy to fish it again, but it's not etched in my mind as the ultimate paradise flat by any means. There's also a similar stretch of water just north of Snake Cay, you can walk up on land past some houses to take a look at it. Didn't fish it.
Of course, with a boat with limited draft/weight for shallow waters on the bight side of Abaco, you will have far more interesting areas to cover than a land-based approach. Frankly, I'm a bit surprised you're looking for new waters, all the places you list, with perhaps Sandy Point in particular, are considered excellent waters for bones.. Have you been to Moore's island? I assume you already have the Abaco Cruising Guide, which has detailed seadrafts of most of the island, even if coverage is a little sporadic on the bight side.