Yes, I know that works. It's just that I thought steps had been taken to avoid the need for quoting hash keys .... that's obviously not so and we're left with what looks like a dog's breakfast when it comes to deciding if a key needs to be quoted or not.
After spending a number of minutes looking at this, the best rule of practice I can come up with is "if the name of the key matches
then quote it" - otherwise there's too many "ifs and buts" involved in trying to determine whether it will work without quotes.