Recommendations on licensing for Rhino plugins

Dear @Avondlicht
I wrote a similar topic quite a while ago:

I never found a ready made solution that allows small quantities at reasonable price and amount of work to implement. I wrote my own painful system which still is to much work to maintain…
still would love to find a ready made solution.

i know there are some rhino plug ins that use devolens former cryptolens.
https://www.softworkz.com looks quite promising as they charge fixed fee - but i do not know anybody with some experience of it…

please report back how you solved it.

kind regards - tom