Advice on my watercooling setup

[Mjolinor]

Stratasys motors are outside of the chamber. Stratasys doesn't print PLA, if you're ABS only you don't need cool air on an E3Dv6.

Stratasys 768 motors are inside the chamber.

PLA is possible if you change the temperatures.

[elmoret]

PLA is possible if you change the temperatures.

Is that speaking from experience or a personal hypothesis?

Stratasys printers don't have a heated bed, so you'll have trouble printing PLA on them - either you'll have to heat the chamber and the hotend will jam, or you'll have to print on a cold bed and you'll get part warp.

PLA has a Tg of 60C, which is where you'd want to set the heated bed (but you can't, and setting the build environment to the polymer's Tg = jammed hotend)