It’s the same error regardless of whether I connect by tailscale IP (100.x.x.x) or the tailscale hostname, and it strongly suggests an issue on the Synology, but everything looks correct on the NAS (but I am by NO MEANS an expert):
mount.nfs: access denied by server while mounting $IP:/volume1/$mount
So, when we drive up to Georgia or South Carolina from Florida, there’s a point on I-75 where the Jesus billboards come out. Many of them are the usual “Babies have heartbeats” variety, but there’s also the following: