The gap between maps in a best-of-three is a genuine pause with no play happening, but a burst of repositioning as everyone digests the result just posted. You quote both sides of the series market through that window around a fair value derived from the new score and each team's remaining map strength. Because nothing can happen while the players are on the break, inventory risk during the window itself is close to zero.
Markets on Polymarket where between-map quoting in best-of series is the natural play: