You can buy their telescopic seatpost, It could have been included in the build list
with new bike order.. ,
upper post and shim are to 26.6, I think..

there are the ones made for the light X series, too, .. Ti.

double pivot brakes have significant MA, higher leverage feels Mushy to some,

Put on a set of 2 finger V brake levers, and the lever's low MA will make the grip feel harder.

also wont have the lever move much .. as low MA pulls a lot of cable..