It was written before IE11 was introduced and never updated. Low priority for any rework. It can be persuaded to work if you set IE11 into compatibility mode, but why bother? It doesn't do anything you cannot achieve manually, but can be really helpful in undoing any customised settings you've made! Most tech savvy users won't go near it as it causes more grief than being useful. Far better to raise your problem here in the Forums and get help from one of the many knowledgeable guys here. M
Superusers are not staff, but they do have a direct line of communication into the business in order to raise issues, concerns and feedback from the community.