[fer]

I'd add to that list Netbird, which is the one I ended up using after trying all of the above.

https://netbird.io/

[ttyprintk]

From the Netbird ShowHN[0], people also mention OpenZiti:

https://news.ycombinator.com/item?id=34310561

[0]: https://news.ycombinator.com/item?id=31551686

[PLG88]

fwiw, OpenZiti is permissively licensed under Apache2.0 as well. I work on the project.