Concatenate multiple Jitter matrices

I'm trying to concatenate multiple Jitter matrices.
I'm looking at jit.concat and jit.glue, but neither do what I want, which is take 6 (or an arbitrary number) matrices and concat them. It is possible with a chain of jit.concat objects or converting to a list and back, but seems very wasteful.

To illustrate, I have matrix A B and C, which are all 2d char
A = 1 2 3
B = 4 5 6 7
C = 8 9 10 11

I want to concat them to create a single matrix = 1 2 3 4 5 6 7 8 9 10 11
There must be something obvious I'm missing here, as I suppose this would be a simple/common function - can somebody point me in the right direction?

Thanks!