Thank you all for replying and helping me to navigate through the LHR during this time. Appreciate all your help! If you have any more pointers please post!

here is another question,
During departure for united it will still be in t2. Is there a quick way to get through security?
I heard you can buy a business class ticket on Heathrow express from paddington to lhr? and use to the quick security lane? Is it valid during this chaotic time there? Or do you have to fly business or first class to enjoy the fast line? And is there a first class /economy class Lane / or priority access line in lhr?

Thanks so much you all