Ok, crazy idea time - what if the multi-Morgan had one station with a fixed platform (not attached to the Z mechanism like the rest), and an optical mouse sensor instead of a hot end? With a printed grid taped to the fixed platform, it could accurately determine its X/Y position via the sensor, independent of motor steps. It wouldn't even need stepper motors at all for X/Y, you could use much cheaper/easier to drive DC motors, with a servo loop in software.
The idea could be applied to a single-station printer, too - mouse sensor would be mounted directly above the hot end, facing upwards, with the "mouse pad" being a ceiling on the printer. The arms could be made a lot thinner than a Morgan normally needs, if the head was spring-loaded upwards so that the sensor rides on the ceiling (which just needs to be made perfectly parallel with the print bed).
The idea could be applied to a single-station printer, too - mouse sensor would be mounted directly above the hot end, facing upwards, with the "mouse pad" being a ceiling on the printer. The arms could be made a lot thinner than a Morgan normally needs, if the head was spring-loaded upwards so that the sensor rides on the ceiling (which just needs to be made perfectly parallel with the print bed).