There are two different situations emerging here. Anchored boats are a different animal then waders in the Trophy area. While there are situations that don't allow you to stay on plane and, because of proximity, you have to slow down. If you're on the upper end on a busy weekend you'll have to bring your lunch to reach the upper end if you slow for every boat anchored or drifting.
Waders are different, not because they are special, but because they are fishing at the destination and boats coming up won't lose any significant time by slowing for them. An "idle" zone wouldn't do any harm there. Several years ago I was fishing beside the ramp in the trophy area and a guy in a bass boat would come well inside my casting range, probably within 25', of me every time he returned from a drift. I had a problem understanding why until I realized he was drifting the other side, so he wanted to mess up my fishing, not hurt his, not that it would have.