They must’ve changed something in the matrix. I swear I posted a reply to this, but it has vanished.
V6 in a bowden configuration is probably the minimum. Though something like the E3D REVO micro might actually package just a bit smaller.
An H2 or hemera might be the largest for a single extruder.
But, it would be good to have a reasonable option for a dual bowden REVO Mini or dual orbiter direct drive.
Also, having acommodations to fit a EBB style CAN board on the carriage would be really great. This significantly simplifies and cleans up wiring to the carriage.
It would also be great to have an option for a rigid mount like the AlumiCore 2.0 that @niget2002 is fiddling around with