Do you place styrofoam or rubber under the tank on uneven surfaces?

I’ve seen a ton of people say that in uneven surfaces it’s better to use styrofoam or rubber under the tank to keep it level - but I hear this mostly with acrylic tanks than with glass. Is there any reason for this? Most say that it evens things out on the stand, but I was always under the impression that the stand is what makes the tank level to began with.

Quote from Avery

This isn’t the case with all tanks, which I’ll outline below;

Glass

Now with glass tanks, all of the pressure is actually applied and spread to the corners of the tank (which is why you have tank stands that only hold the tanks on the corners fully). Placing mats underneath aren’t recommend since it can shift weight over time, and apply all of the pressure from the corners to other parts - which under pressure/tension, will crack the glass.

Acrylic

Aryclic tanks actually spread the weight out from the bottom to the sides. These must have a completely even stand/bottom, where any imperfection on the weight being distributed on the tank can cause some unevenness and will put more water pressure on other aspects. Since it’s acyclic, it won’t specific break, but it will cause for the sides to bow outward more where there is uneven weight and can cause for the acyclic to deform over time (and thus causing for a weak spot where it will break at - but extremely rare).

Thank you for the huge explanation. I always wondered why it was even a thing, but makes sense if it came from acrylic tanks and then people thought it might make more sense for glass tanks too.