Proof of work below, showing GQRX on a MacBook Air with WCBN-FM 88.3 tuned in, with WEMU-FM 89.1 adjacent, via a Tailscale VPN connection to an rtl-sdr running on a Pi 4 under Ubuntu 20.04 LTS arm64.
The antenna I'm using is my 2 meter antenna, which should usually mean that FM signals are unwanted noise - for now they are ok.
On the Pi 4 one Tailscale process is pinned at about 70% CPU, so it's working hard to keep up the VPN stream. I am not noticing any lag or dropouts, though, and the actual rtl_tcp process that's decoding the radio is not so busy. When I switch over from Tailscale to normal unencrypted streams, the CPU quiets way down. I have a feeling there's more to be squeezed out of the arm64 cores on the Pi 4.