Please do keep it alive. The VPN bug makes this ROM pretty much useless despite all of the other strengths it has.
I'm not a developer, but I can't help but wonder if the newest security patch might not fix that and VoLTE. It seems to have done that for stock S7 ROMs.
Update: May 5th security patch on lineage-15.1-20180606-UNOFFICIAL-a3xeltexx does not solve the (Orbot) vpn problem.
The orbot vpn issue appears to be a bug in the app as it appears to affect quite a few devices running lineageos.
I did have a play with it and there was nothing obvious in the logs it created, one thing I did spot is that it needs the storage permission for the VPN to work (can be enabled in app->permissions). Once enabled it did connect but I couldn't get any internet.
I regularly use OpenVPN on my phone without issue so I think this must be a Tor or Orbot issue, neither of which I can fix.