I’m only just starting my Air Manager journey, so I have nothing completed yet. To begin with I’m adapting existing instruments for my specific purposes, so whether or not I can distribute those will depend on getting clear permission from the original author (or the presence of a clear license). I’m most likely to work on some original panels for the Just Flight Avro RJ variants of the BAe 146, when they arrive.
I am certainly frustrated with the tooling available, and I’m looking at options there, at the very least using a better editor / IDE to create the code (and some existing creators do use Visual Studio Code etc) but to create a visual designer would be a complicated task. It should in theory be possible to build such a thing in Visual Studio. You could potentially translate XAML from the visual designer there into Air Manager code. But I haven’t got the first idea about how to go about that right now. It’s an area I will investigate, though.
Supposedly SimInnovations are working on the editor side of things so they may yet deliver something closer to what you want. I think it’s important not to over-complicate the platform, though.