Encounters warp the story shape and add to the danger of pure randomness. Ramping up the spell use makes them more dangerous and dramatic.
There is the advantage that all of those not running short enough prepare their spells. A few laments that they could not know what they faced better will help. Also, healing spells can be cranked up at short notice.
Plus I have to figure out how to get the characters throwing spells where the point of view character can't count them. Then they can just announce they are growing short. Though she does notice that one character is holding back.
Maybe I should just crank them down in level.