+1 : for a folding bike, the weight is very important because many people need to carry their bike.

11.38 may seems not heavy but remember that this a "naked bike" weight, for a utility bike you need to add something to carry things (rack, front block... using a rucksack isn't an option for a utility bike), mudguards (a must to keep your clothes clean), lighting (a utility bike must be usable 365 days a year, 12 hours a day, also in the winter, also at night).

I would never use a carbon seatpost on a folder because :
- the seatpost will be dirty, if the seatpost is lowered while dirty, it will be damaged quick;y.
- carbon doesn't like repetitive compression/decompression cycles as it happen when locking/unlocking the seatpost on a folder. I know Brompton users having to do that 6, 8 times every day !