But they fold some. my BF PL has a QR that holds the rear end and the seat mast,
once it is loosened rear and seat mast fold. it's part of the travel packing procedure.
so a bit stiff, , I happened to get the folding handle bar mast, that option folds down,
adjusts in height and uses a normal threadless stem, so bar choice is wide open.

Tikit has an advantage for IG hub drivetrains (season tikit)
as the BB Shell is part of the rear portion, Black in Vic's picture ..
For the 20" wheel line, the hinge is behind the BB, which is part of the main frame.

so my BF PL has a chain-tensioner , even though it has an IGH.