] 33.062 Holder may exchange commodity cards for treasury tokens. ... This
] can be done at any point in the game except when acquiring civilization advances.

I would guess that would be the entire phase (the 15th phase). Which would mean a player wishing to use this ability, could hold up the prior phase, work out what he wants to do with discarding and purchasing, and then do what he needs to do in the Acquire-Civilization-Cards-&-Return-Excess phase.

How about this instead?

"33.062 Holder may exchange commodity cards for treasury tokens. ... During the Acquire Civilization Cards phase, this can only be done before the player acquires his first Civilization Advance for the turn."