the SaaS suggestion is for future consideration. if you have been actively coding for 30+ years (like many of us) then you are able to adapt to modern times. we are moving/moved to an "always on" life, even in the woods. i am sure you are a great programmer, but you are not Facebook or Google. their biggest products are SaaS.
regarding source encryption, i've used this before:
https://www.sourceguardian.com/
my favorite used to be source cop, but i couldn't get license renewal for about a decade. now it looks like they are coming out with a new version at some point.
SourceCop 2020 - Coming Soon
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