Eh, I'd say that's pretty insignificant to a CS pro, in the same way learning what every hero/champ does in DotA/LoL seems daunting at first but is pretty trivi

Eh, I'd say that's pretty insignificant to a CS pro, in the same way learning what every hero/champ does in DotA/LoL seems daunting at first but is pretty trivial once you have 1,000+ hours in the game. You're just incrementally building on knowledge that you've accrued while playing normally. It's not like a pro has to sit down and do some huge exercise in rote memorisation for smokes and flashes every week. Maybe rarely when a new map gets added to the active pool.