Mounting through Bonjour has not yet been implemented, as of this moment I do not quite now to.
I just created something somewhat related to this: A mechanism that uses several ways to identify servers and server aliases. Meaning CMN can now see if existing mounts match a certain server where it looks for aliases on the network. For example MyServer vs 192.168.1.100 (even for NAS devices with multiple Ethernet ports and IP Addresses).
While creating this, I was unable to find a way to mount through Bonjour.
From what I have found:
Bonjour itself does not mount network shares and is therefor not any faster than a regular mount.
Bonjour is only for service discovery, not for mounting.
The actual mount speed depends on the file sharing protocol (SMB, AFP, NFS, etc), network latency, authentication, and DNS performance — not Bonjour itself.
So for Finder to be faster going through the steps:
1) Finder sees (eventually) servers in the network (not always all that reliable mind you)
2) On seeing a server it may right away determine available shares (and cache these or not?)
3) The actually mount process appears not any slower or faster than CMN does, especially when using API calls, as Finder uses the same calls.
This is the best I could find.
It would however be interesting how Finder mounts a share this fast.
Also something to think about: CMN does async mounting.
A call is send to the macOS framework to request a mount, and then CMN goes into a waiting mode until macOS sends a notification. There will be a delay, as macOS doesn't send the notification instantly. Maybe this is where we perceive a delay?