I wonder whether wyBuild uses LimeLM for its licensing.
We currently use a precursor to LimeLM. We're seamlessly switching to LimeLM in wyBuild 2.7.0.
It appears LimeLM runs on a server under your control. This would mean that in the unfortunate event anything were to happen to you, wyBuild would then cease to work for me.
wyBuild will only contact the servers on activation. All other times you can run wyBuild completely disconnected from the internet.
We're doing very well financially, but if you're still worried we can talk about source code escrow.