Able to use ER8 collet?

Is it possible to swap the single-diameter chuck on the CNC head of the Original model with an ER11 collet?

I managed to find one that can fasten to a 5mm-diameter shaft, but it’s too wide for the hole in the CNC head’s enclosure, and the motor on there has a 3mm shaft.

Is this completely unsupported, or is it possible?