I can't see you having much luck without a heavy price tag attached to it.
To be honest the best option I found with my X2 machine is to use a direct collet when I need it a bit closer tolerance.
I can get anywhere between 0.004mm to 0.04mm throwing a cutter into a decent ER32 chuck and locking it up.
With a direct collet I can get anywhere from 0.004mm to 0.01mm.