I think that's true, but I have basically 0 confidence that I can implement even simple rules using it, let alone anything more complicated.
The thing that was the real show stopper for me and made me switch to Nebula was that there doesn't seem to be a way to self-host a backup controller so that our network can continue to function even if ZeroTier.com is having problems. Unless, that is, I go entirely self-hosted and give up the web management UI, which I think is part of the compelling offer of ZeroTier.