Can't tell you what to do but I wear a head sock and the helmet skirt and have for years. Prior to the new rules I also wore the neck "horse" collar which was covered in nomex. The more the fire protection I could wear, I did........Good Luck
My helmet per the rules has a nomex liner, I then ear a nomex head sock, then use a nomex covered neck (horse) collar,, and my cars are equip ed with containment seats that have the required lateral movement head and neck restaints all covered in fire resistant/re tardent material.
These are precautions are in the rules to help keep any flame from entering the helmet around the openings...
Don't skimp on a $30 piece of insurance (most head socks can be bought for that)
Charles