hmm, i’ve checked and according to the figures, the ragleys chainstays are the same length as mine – 16.5″. Not sure why they felt longer, they certainly looked longer – the f. mech was definitely further away from the tyre. Maybe it was the steeper seat angle??
I’m pretty sure slack angles have been around for a while. My old Cove Stiffee had them back in 2002.
I recommend building the test/demo bikes with a longer steerer and some spacers though. Takes a bit too much getting used to for people on non-on-one bikes otherwise (unless thats the idea, like making people use a shorter stem?)