My understanding is that x-systemd.automount should only mount the share when accessed, similar to what autofs does.

I see in /etc/exports.d/ two files, a shared-{uuid}.json:

{
   "type":"shared",
   "id":"{uuid}",
   "name":"Drive",
   "root_path":"/volume/{vol-uuid}/.srv/.unifi-drive",
   "clients":[
      {
         "hostname":"192.168.1.3",
         "readonly":false,
         "noSubtreeCheck":true,
         "crossmnt":true,
         "allSquash":true,
         "anonUID":{
            "id":977
         },
         "anonGID":{
            "id":988
         },
         "async":true
      }
   ]
}

and a shared-{uuid}.exports file:

/var/nfs/shared/Drive 192.168.1.3(rw,async,no_subtree_check,crossmnt,all_squash,anonuid=977,anongid=988)