zfs_expire_snapshot=300 causing 'Stale file handle' over NFS

[youzhongyang]

Once a snapshot is accessed through the path .zfs/snapshot//..., it may get unmounted on the server side due to the default 300 seconds of zfs_expire_snapshot, which can certainly lead to 'stale file handle' when it is accessed again.

On illumos, I don't see this kind of auto-unmounting of zfs snapshot, is there any reason why it is done this way in current openzfs? can I propose changing the default value of zfs_expire_snapshot to 0, i.e. disabling it?