AFAIK you’re right, Stallman only cares about free as in freedom, which means at a minimum the source code should come with the product so you can modify it and inspect it. If you can figure out a way to sell it like that, and not just sell tech support, I’m sure he’d be all for it.
This is the one! This is why I wanted boost in the first place. For now I’ll just keep using Sync, which has this. I don’t need full feature parity with the old app, but this one is especially important since lemmy is so much slower paced than Reddit.