Your experience matches mine. I love the product, but I do miss the staying power of Dektol. My reaction to the situation has been to go with the lower dilution and replenishing. While I obviously don't have the throughput you have, such a tactic might work. There is, of course, the possible argument of going back to a hydroquinone based developer (LPD is one of them) as you will be putting a smaller amount of developer down the drain.