Good Morning Zelda, One thing you may want to do to help Walter is to test a couple of times between 2+ and 6+. If he's showing any downward trending feed him some LC+MC to slow things down. Once he hits the lagoon he's going to get out his big trampoline and prepare for his moonshot...even if he only goes as far as some mid-range blues he needs to ease into these low numbers...and hopefully some mid-range blues would be easier on his system than visiting the lagoon, which seems to send him soaring.
If you're not home, leave the food in the auto-feeder so he can snack and avoid those low numbers - at least for now...until he becomes more accustomed to the lower numbers.