A partly related question: I have seen loading caps both with rubber gasket and without (the former way more common). Since you always want to acoustically separate different drivers fom each other, especially bass from tweeter, I find a gasket a reasonable part here, either to the loading cap or to the rear cover.
I have never seen a gasket attached to the rear cover.
And if the loading cap is removed it feels like the risk for sound pressure in the box to affect the hf diaphgram is increased.

Anyone here that has some thought about this?