Unless this is open source I don't see the point.

We can't trust closed source software for content creation tools.

What happens when he gets bored?

However, I LOVE C# and would totally be down to contribute if it's open source.

".fla / XFL import — This is the one I’m most proud of. You can open your old Flash files. As far as I know, this is the only open-source tool that functions as a full authoring environment and can actually import .fla files. Not just play them back — edit them."

as to when they share the source, idk!