Pi Lab has survived the first upgrade to the latest version of Bludit.
I was concerned how this would go since I had things running so smoothly.
It worked perfectly!
Pi Lab is now setup to have a "source copy" on the main node that allows me to work on that version without affecting the live site. Once I have it working I simply run a script that I wrote to "promote" this "source copy" to all of the nodes. It also creates a backup on GitHub. This gives me full redundancy and a keeps a historical record of any changes that I make.
The upgrade was as simple as copying the new version over my "source copy" of Pi Lab and then running my "promote" script.
Checkout the Pi Lab Setup for more information.