The hub is not wider than the Nimbus 36" Nightrider, the wheel is dished to allow for the hub fitting. This gives the same offset from the centre on the none disc side and about the same offset as a none wide hub on the disc side. The wheel seams very stable with this combination and through testing has shown great durability.
The Handle can take some hammering… I dropped the prototype at about 17mph on the Dosseldorf Marathon and there was no damage at all. That was even with unhardened ‘T’ sections. Should they break/bend they are easily replaced, the design is that they should be sacraficial in a really bad crash and protect the base part from damage.
Canada should have some of the Impulse unicycles, they just take time to get on the site with time differences etc.
It will be hard to upgrade a nightrider to disc as it does not have the bosses for mounting the calliper or the cable support (although that is less of a problem). The shadow is upgradable without a problem on any existing 36", you may need a different seatpost though for the KH as it is 27.2 or a shim.