Lol, you nailed it. Some people say this and some say that but seldom will you be able to lock it down.
To your follow up on your question, yes, lots of different sized cabinets with different sized ports, some round, some slots, and the 26 m/s worked without issues. Don’t go giving me credit for the 26 m/s rule though, others have used it before.
Here’s an example of a slotted port I built recently (these are test cabinets for some desktops I may start selling in the near future). This one was a bit of a challenge due to the length I needed for the desired tuning (sidewall removed to show it). I pushed the driver to it’s mechanical limits and there was no audible chuffing from the vent.