The Supplemental Update took ages to install on my SSD-equipped 5k iMac (it's only about a year old). In fact, I'm quite sure it took longer to install than Hig

The Supplemental Update took ages to install on my SSD-equipped 5k iMac (it's only about a year old). In fact, I'm quite sure it took longer to install than High Sierra itself, which is quite an achievement because the High Sierra install involved upgrading my filesystem to APFS! Maybe I just found myself more annoyed than usual because I clicked "try later tonight" for the supplemental update prompt when using the computer the day before, and then when I tried to use the computer in the morning, it went about its installing business which featured 2 backwards-moving progress bars and took at least 20 minutes, while I sat around twiddling my thumbs waiting to use my computer for what should have been a simple task. I'm not sure if this is normal behavior when you postpone an update and then wake from sleep later, but I've never seen what effectively turned into an un-prompted forced install before.