The title of your post caught my attention. Did you use 8x Hemera for Chimeras on all four Toolchanger heads? Is there a way to get around Duet3's six stepper drivers to make that happen?
You can use Duet 3 EXP3HC expansion boards to provide additional stepper driver, heater and fan outputs.
I tried deleting my original post but couldnt so i changed it to that. I have 2 tools as chimeras and 2 Hemeras and i was able to squeze a valcano on it. a total of seven tools. Working on the external steppers now but did some calibration prints with the chimeras and I recommend it. Having 4 tools only using 2 spaces is cool.
im working on the part cooling for the chimera and the extra steppers. I also need the metal guides for the wires.