I'm not sure about beta blockers, but Adderall doesn't do well for games - it's more suited to holding down attention on things like spreadsheets. Modafinil doesn't work nearly as well as sleep. It helps in learning, but not so much on the battlefield, unless someone had an all nighter.

A few cups of tea might just do all of these better than drugs would. And things like L Theanine or creatine don't really need to be banned.

Many professional tournaments have everyone playing on the exact same hardware for this reason. You bring your keyboard/mouse and everything else is identical between competitors.

Great point, thanks for your input!