I did follow your guide command for command, step by step, skipping nothing. Booted the switch with a console cable, smashed 'b' until it dropped me to a prompt. Exactly as written - or I tried. But they were invalid commands. I rebooted the switch a couple of times to be sure I didn't miss the bootloader. I assume because of being on really old firmware? (version 07.4.00dT31 ) For example "setenv" was an unknown command so I couldn't set the ip. "update_primary" wasn't valid either. I used the '?' menu to pull up lists of commands and dug through the menus until I found different commands that let me set the IP. Once I did that, update_primary still didn't work because it was an unknown command but I could do it through the webui. Once I updated the primary and rebooted and smashed 'b' to get to the prompt, the commands in your guide worked exactly as listed and I was able to fully update and set up the switch. The guide was fantastic once I got to newer firmware, and it showed me what I needed to do to get to a newer firmware to be able to use the guide, so I consider it a resounding success!

I'm only guessing it's due to older firmware, all I know is that the commands listed were unknown until I got to newer firmware. In the end tho, the switch works exactly as you described and your guide was very clear and easy to follow!