Man, I reeeeeally would be glad if ED eventually introduces realistic INS drift and complete GPS/INS blending with Kalman filtering, as PMDG already does. It might not be a huge deal in A-10C, but defenitively it would be a major change in BlackShark, forcing us to plan and make INS corrections here and there. Olgerd has come up the topic once, and it seems to be a WIP, I'm still hoping it will be introduced in future patches.
Regards!