Update on this after trying it for a while. I’m only really doing PLA and some PETG printing, but I’ve had no problems at all exhausting outside. It seems to keep temps down well for PLA (**but I haven’t done a large print with PLA yet) so there’s no need to even open the door to reduce heat. Unfortunately no tests with ABS yet, so I’ve no idea if the temps required can still be maintained.
I feel like I already mentioned this somewhere but here it is again anyway…
I used this for the vent:
This fan inline with the exhaust pipe (which I recommend using the metal dryer ones designed to take heat, rather than plastic ones):
Generally I keep it near the lowest speed setting, but it’s nice to crank up the speed if you want to be sure you’ve pulled the gross air out after a print is over.
For the exhaust connector I used the one on the Bambu wiki, but it doesn’t fit very well on an X1C so I recommend finding an alternative for that.