I wish more places operated like this here in Australia. Sadly the consensus at every single company I've ever worked for is if you don't have an IDE, debugger or textpad instance open on your screen you're slacking off. You don't succeed in business by burning out the talent that drives your company, you nurture it and if 20% of spare time yields you no result 80% of the time you'll be getting better output from your team because they're focused.