I saw a lot ot posts saying that Tap VPNs would stop working in future versions of macOS due to Apple's end of support for system extensions. As these messages are not recent, I wonder if some updated information is available somewhere. I've already read the post on the Tunnelblick web page... Some tests make me think that tap interfaces can still be used in Tahoe. In addition, there is the tun-rs project (
https://github.com/tun-rs/tun-rs) proposing tap implementation over feth interfaces (with some specific benaviors, so with some adaptations needed to get it work with openvpn).