Exe junction box in an I.S. circuit

If I have say a klippon Exe junction box that is to be used in an I.S. circuit, do I still have to put on Exe glands and maintain the IP rating of the box with washers if req'd?

I know a normal I.S. circuit only needs an IP of 20 and any industrial gland will do, but do you still have to respect the Exe rating on the box?

Ideally the box should be marked with I.S. circuits to indicate it's not a "normal" circuit box.

Thing is, if I knocked off the certification label then I could use the same criteria for a normal I.S. circuit.

Thanks for any insight given.