Gender imbalance is an issue, but forcing panels to be unrepresentative of the fields they're discussing is hardly going to fix it. The fundamental issue is that notable people in technology are almost entirely male. We need to encourage girls to come into technology fields at the bottom. Perhaps ensuring public panels contain notable female role models would be a way of doing that, but if the panels purpose is for very specific technical discussion arbitrarily increasing female participation to levels significantly above what is representative of the field being discussed isn't really going to help anything.