I have 1G/35M at home, but have a relative with symmetrical 2G. I duplicated my QNAP box and hooked it into a hEX at their place, then set up two WG tunnels between it and my 5009; traffic to .124/24 on my end ends up on their end, traffic to .126/24 on their end ends up on mine.
But I also expected to do QNAP RTRR backups and NFS mounts from them to me and only getting ~175Mbits/sec thruput, and was surprised at such a slowdown, also verified via iPerf3. One thing I noticed in /ip/firewall/connections is there's no Fastrack on either side of this tunnel. If I dst-nat a hole from my side's external IP to the iPerf server on their side (i.e., bypassing the local-network tunnel) speeds are in the ~750Mbit range, as expected, so it's not a thruput issue per se.