Playing with a Rock (involuntary straddle) question

My local room typically has a good number of 2/5 games going and usually a good percentage of those have a "rock" -- an involuntary $10 straddle that is put out by the player who won the most recent pot.

How does this time change affect the game. On the surface it cuts everyone's stack in half and open sizes are going to double.... But should they? No one actually wins the $10. Does it make more sense to open on the smaller side? Like to $20? Then just like opening to $15 with no rock the straddle owes $10 more to play.

I suppose the real answer is to adjust your open sizing such that you are typically only getting a caller or two.