It's a useful feature, to be sure, but is there any way to disable it?
For instance, if the form is a single text field and already has a "clear" button beside it, it's superfluous to also have the X. In this situation, it would be better to remove it.
Can it be done, and if so, how?
Style the ::-ms-clear
pseudo-element for the box:
.someinput::-ms-clear {
display: none;
}