its back again....
We went through all this same subject on the PA forums, when the MNPAL enforced the "no modification" rule.
If you cut off/remove any item from the mask that was originally designed to be a "feature" of that mask ( including chin straps ), then you are modifying it. And as such, the manufacturer will not warrant it, and it is no longer certified. If you wear it in any way, other than that directed in the instructions , you are releasing the manufacturer of any liability, and it is no longer certified. If you bend or mis-shape it , then it is modified. Even to the point where I have had players told to change goggles because they were bent out of shape from being pressed in the kit bag. Remember the JT Ize goggles? Look at them too hard and they bent out of shape.
If you replace any standard item with another standard replacement item ( such as a new lens, or soft ears, because they are a manufacturer direct replacement item ) then the mask would not be modified, and therefore certified.
Rob.