How can I have custom Finder Icons for NFS Volumes (like SMB icons)?

I have a few NAS/UNRAID servers that I connected to from my macOS (Ventura) client over SMB, but I'm currently swapping over to NFS. From the command line, things are fine and work as expected. However, on my Desktop, the custom icons I had for the shares/volumes are gone (replaced with the default), and I can't seem to put them back using the technique outlined here , for example. I've tried ICNS & PNG files, and these worked just fine with SMB (and still do). Are custom Volume icons not supported for NFS?