So, in case anyone is interested in my little project here, I've managed to export some of the textures for my local area and get them working in my Unity world, as well as grabbing the height data from FG now instead of the custom terrain server I was using originally.
As you can see, it's still using the chunky 90m terrain, and my height sampling gets glitchy here and there (hence the needle problem down by the corner of the skybox). It's also slower than cold molasses when it comes to making the skyboxes and doing the terrain sampling, but I have a long list of planned optimizations and improvements going forward from here. Even as is, however, it should still be adequate for a player moving at normal human speed.
I have downloads available (currently windows only) if anyone really wants to try it - but the whole thing is so primitive at the moment that I'm not even gonna put up a link unless somebody REALLY wants to see it.
My flightgear build also has a bunch of fg_data in it that needs to be weeded down - currently the DL is over 800 megs.
We're definitely starting to have fun now, though!
Gratuitous thanks, again, to everyone who's ever worked on FlightGear, this is an
amazing piece of software you all have created!!!