I've used it a fair few times, mainly to try out places we wouldn't normally eat at, like some lesser known independently run restaurants, which is supposed to be the point of the scheme.
I've seen some of the queues at the big chains and it's ridiculous. They definitely shouldn't be included in the scheme, they'll survive no matter what the global situation is.
Hopefully it isn't extended into September. As ever when you give a inch, entitled cunts take a mile. I read an article the other day about someone who couldn't be seated because the place was fully booked, so they kicked off and demanded to come back the next day (when the scheme wasn't on) and have their 50% off.