This is already here in 2.25+
Go into Settings > Network > Connections and look toward the bottom for "Local Address".
There's a little button next to it, click it and find your VPN adapter name.
I fixed this with my final choice, after numerous test, due to fastest speeds (only 50% of my bandwidth not 25% with all others for PtP; ExpressVPN.
I applied tunneling and use it to only apply to Tixati and set to disable when disconnected.