I had one for a bit a couple years ago. Geetech A10M.
^*%^*%*&^)(*&(*&(*^&$^%$%$
and
*()&(*^*&%&$&$*&^(*&)(*)*(&*&%
and
)(&^*%*%^(*&)((^*%&$&^%*&^(*&(*
Just about covers THAT idea.
They might be OK with dual or triple nozzles, but this whole idea of retract that far then feed the 2nd color/material into a common nozzle is damn near impossible to dial in with any accuracy. And even when you do finally get rid of the gaps and "farts" from switching filaments there is color bleed in blobs for the next dozen or so layers.
OTOH, Kingroon is down to 169 bucks for a KP3S up here so I tossed one into my Amazon cart for the next order. Fairly reliable and the perfect size for making coaster cases, feet, plaque holders ect for the laser.