After mullvad disabled port forwarding, I switched to AirVPN and it works fine. I trust it slightly less than Mullvad but I'm avoiding copyright trolls, not three letter agencies.
They have a good record of responding to various restrictive legislation around the world (eg pulling out of Italy after they passed an overly broad 'anti-piracy' law) and also haven't had any open scandals. That's about as good as I can really expect considering that I'm mostly just not interested in my local ISP knowing what I'm up to, and am not doing anything hugely illegal or pirating at a large scale.
For reference, the VPN I used before then offered no real controls besides a limited country selection and a randomly assigned port forward. It was bought up by a company owned by a guy known for running scams, after which I switched out. Now having seen all the customization I was missing out on, I can't really go back to a simpler VPN.