Logic

In Opponent.QueueNewCards, there is a conditional check to determine whether or not the opponent will queue up new cards:

if (this.NumTurnsTaken < this.TurnPlan.Count) {
	// logic for queueing new cards
}

This mod will reset NumTurnsTaken back to zero once NumTurnsTaken is greater than or equal to TurnPlan.Count, allowing the opponent to forever queue up cards.

Notes

This does not randomize which set of cards the opponent will play. Meaning, if you play an opponent long enough, you can memorize which cards come next.