I like the resourcefulness and re-use!
As drawn, the tube is in the same space as the side panel thickness, so that exact location isn't viable. But generally speaking, I don't see any problems with having the port off-center.
Maybe consider placing it centered horizontally left/right, and vertically just above the woofer magnet? Although the top ~ 1/3 of the port would then "overlap" the back of the tweeter, even that overlap portion would still clear the tweeter magnet by 18mm. Seems like such partial "blockage" wouldn't meaningfully inhibit air flow to the port.
EDIT: looking more closely at the driver dimensions, there is > 55mm distance between the woofer magnet and tweeter magnet. So the port would fit there, and have pretty good clearance to the front panel, but overlap a bit of the woofer chassis.
Maybe the best option is centered between the driver magnets vertically, and then offset only ~ 3cm left or right? That should provide ample clearance to the side panel (and any damping material there), as well as both driver chassis.