Guess it’s not lockable - and it wouldn’t be helpful, the front wheel can’t be inline with the rear wheel. To roll it along you’ll have to lift the front wheel.
Of course is the locking latch in danger to be damaged by touching the ground; Valentin replied at kickstarter to a request from Sang Jin regarding this issue:
My suggestion would be to use two very small wheels (rolls) - similar to Brompton - left and right the latch.
I’ve heard from a delevoper’s team member that they didn’t receive the serial tube material by now, so I mean it’s just honest not to claim a certain weight. Expected are below 12 kgs for Urbano and Rocky, Valentin wrote at a German bikeforum that they want to keep the Speedster’s weight below 9,5 kgs.