I do believe that the information you are referring to is presented in one of the instructional dialog boxes that appears before you actually start to create the Live USB.
Yes it is on the front page ..... and is emboldened to draw your attention to it.
A different method of checking the chosen partition is suitable will be tried. Hopefully that will overcome the problem of the warning being ignored.
ext2, ext3 and ext4 all have the same ID ..... 83