I suspect the reason the N8 firmware is still being offered for ONE users is this. Apparently, even with N8 AND version 8 maps, ONE units will NOT support IQ routing and Advance Lane guidance. So, these options (I think) aren't even being shown in the firmware release for ONES.
But, they are were being shown as choices for x20 users who downloaded the firmware since, with N8 AND version 8 maps, x20 units WILL be able to have those features on their maps.
The problem is that no official version 8 maps have been released for x20 units but x20 owners who downloaded N8 saw the options in the new firmware, and immediately started bombarding TT with calls saying ALG wasn't working!
So, TT pulled the N8 release.
Unfortunately, the N8 release killed custom menu items like Itinerary Planning for some, killed VR for others, and lottsa other stuff.
The reference to ONE'S non support of the features is here (from a staff member of a Brit forum, Darren, who said in a post:
"However, as the latest recently announced ONE models DO NOT support IQ routes and ALG even with a v8 map, it is reasonable to assume that all ONE devices will be denied this facility even if a V8 map is installed."