Those sorbys are so long you may want to wear it on your back like he did in Braveheart, otherwise it might trip you.

but seriously, I have a smaller chisel I carry when I climb -- quite often I find that I don't need or want a big chisel when I am fine tuning a timber in the air -- there is often not a lot of clearance for a 1-1/2" or 2" chisel to operate.

that being said, Barr sells one for his chisels . It would be too short for a Sorby, but it will give you an idea of what his is like. It has no way to secure the chisel, relying on friction and gravity.