Performing live for any singer can be a nightmare and I don't blame Beyonce one bit for choosing to mime. If I had been her and I had to sing live on such an occasion I should have refused too.
At the age of 16 I sang live in the first British opera on UK TV, The Turn of The Screw by Benjamin Britten in 1959. Because of time lapse the orchestra was in one studio and we sung live in another with the help of monitors and a spare conductor.
The studio was dead. We couldn't hear ourselves sing. We rehearsed from 7 am and recorded at 8 pm. The performance went out as if live with all mistakes. No editing was possible. It cost a fortune.
The first Act went well but on the second a camera went wrong and panic ensued. We were 'live'. We could not stop, our monitors were cut off from sight as the production was changed. We could no longer see the conductor. He had vanished. It says a lots for our soprano Jennifer Vyvyan that she never batted an eyelid.
The result under the circumstances was exceptional and the world never knew but I did. At 16 I vowed never to do this again. Even today the thought of going through that again scares me stiff.
Today audiences expect good sound and that means studio sound. I hate live performances as the balance is usually wrong and always under-rehearsed.
If you want live sound my answer is - you go and sing it live yourself.