In your recent change log you mention querying External Lists. Are you referring to BCS External Content Type External Lists? If so do you have any intentions of making DFFS work with such lists so that DFFS can be used to customize their forms?
I haven’t tried since version 3.x. Cant remember specifically which version since it has been a couple of years but I know it didn’t work back then. I’ll be setting up a new BCS list at which point i can retry with your latest version.