It should work if you set the UDISKS_IGNORE attribute over udev rule, see x-gvfs-hide not working for specific partition (due to it being LUKS type?) (#587) · Issues · GNOME / gvfs · GitLab.
The dummy entry doesn’t work as the logic for crypto blocks doesn’t read those options currently:
But maybe the logic could be changed to take this into account, just I am not sure that such a dummy entry won’t have some unwanted side-effects…