Unignore works fine from the contacts tab in my experience.
Or am I missing something here?
If a material or fragment isn't
in your contacts tab you can't ignore it. So if you are about to head out and you remember that you previously ignored something then bad luck you need to wait until you find one - and then remember to pay attention to it in amongst all the other materials and limpets flying about - to unignore it.
Plus as mentioned by
YinYin the contacts list reorders itself quite often and it can be hard to select a specific thing.
Mining was supposed to be "improved" by this patch. If limpets are blocked because they are carrying an unignored material that you can't jettison, the only way to unblock them would be to destruct all the controller's limpets - which in practice means all active limpets since you would have to guess which limpet is managed by which controller - so things are actually
worse than before. At least you could shuffle around the refinery or materials tab dumping stuff to make room for more of the same.