Maybe I misread your comment, I thought you were talking about AirVPN vs Mullvad.

Anyways the C code in that repo looks like it’s just libraries they have vendored in, not specifically stuff they are writing (which a lot of apps do, but usually dont include directly in their repos), but I could be wrong didn’t look that hard.

And you can still always use a different client (I know you can with AirVPN, I assume ivpn is the same).