Thanks. I'm hardly desperate to update so I'll just leave it alone.
The guide is definitely problematic. I didn't realise there were two different versions of the guide - I followed an older version using an older NAND dumper and required injecting uLaunch using a PC. I was able to revert to doing it the 'new' way and I'm good to go now, but I ended up with a NAND dump without the .sha file thanks to the outdated guide. Luckily I was able to do without it but there were a few heart-in-mouth moments.