I was able to get back to the switch today. Fortunately it had an IP address. I was able to telnet to it and was not getting the flood of error messages there. That is, not until I executed the command to copy in the new bootram image and then the same flood started.
I experimented and confirmed that console keystrokes were getting accepted and that I could execute commands entered "blindly". Each echoed keystroke was quickly swept away out of sight but I managed to complete all the upgrade steps.
The flood of error messages went away upon reboot on the final SPS image and the doorbell and AP all got powered up.
So, at least for now, the switch seems to be running OK on the recommened Lennar firmware version. I will return here if that changes.
