I've been thinking about this long before these were released. I had always thought that the gMax's top horizontal rail (where the filament spools and LCD are mounted) would make a great mounting point for multiple bowden extruders with tubing moving down to a light carriage. For something like the Kraken, with 4 extruders that would be quite necessary.
Then I started actually using a Bowden setup with my Cohesion printer. Decent results but lots of leaking filament. Long retracts are required, etc... Now I try to avoid bowden whenever possible.
But it will work, and you can mount bowden extruders to that top rail of your gmax, you just need to design some mounting brackets.
Thanks Chris - I haven't ordered any, as I've just gotten multiple v6's, but if Cohesion takes off I'll definitely create Chimera and Kraken toolheads. I was going to make them direct drive but that will prove difficult. Bowden it is, just keep the tubing length as reasonably short as possible, that's really all that can be done.
As far as cyclops - retractions are the easiest part. It's handling support for people with issues that will prove difficult. Plus, as they explicitly state, it's problematic for materials of different temps, and that eliminates the PLA/ PVA support from working in a Cyclops. I print PLA at 220 - 230 while PVA needs to be at 190 as it decomposes at 200.