Wow, that's very interesting.
One thing I would like to ask though. We are still using Linked clones and not instant clones. Would we be facing the exact same issue as the linked clone machines are not being deleted after use, we just do a refresh after using it.
If so, I will try and get together with my colleague to see if we can test this with a few pools.
One thing to keep in mind for us is that we see this behavior the entire day and during the morning we do have a lot of people logging on but not really logging off.
Also, we saw a timestamp of about 3 minutes that it took a user to logon with the gasp in it but during that period of time a few other users were able to log in correctly without any delay. If the SMB lock would indeed be activated during shutdown of a machine wouldn't all logons during that period be slow??