I asked if stacking should be avoided because of heat and @Daniel_Francis told that heat would not be an issue for a stacked Cascade.
Also, in a video I can’t find right now, either @Daniel or @Jonathan_Gullman said they experimented with stacking and found the could measure a difference between a stacked and a shelved Cascade but that they could not hear a difference.
I’ve haven’t seen anywhere where MSB says that stacking should be avoided. MSB shows them stacked on the MSB website.