The biggest issue I see with a 660 CFM is that it is over 3 times the referenced speed of the built-in fan (200 CFM). With longer ducting (flexible over semi-rigid or rigid) the air resistance and flow dynamics will decrease the 660 CFM, but you will need to calculate how much air movement the vent fan needs to produce to get at least 200 CFM actual end of hose output.
That might cause some hardware issues in attempting to drive the fan at 3 times its normal design. Also, you will increase the noise level of that fan (even though it is not trying to increase its own RPM).
Another thing is, with 3 times the potential air flow (internally) smaller pieces are going to become air borne inside the Glowforge.
There are some calculation sites to help (a bit HVAC centric), but can be done: