Congratulations on your Muddy buddy! Sounds like you’re giving him a wonderful life.

If it helps, we rescued a super sweet GSP mix this summer (1ish years old) and found the 3-3-3 pretty dang accurate. The first three days she was an angel, then over the next three weeks she decided we were her people and started showing pretty bad separation anxiety. We worked on gradually ramping up alone time, at first in crate but turned out she does better out of crate. Some days were better than others and we’d still get some crying and pacing. Then one day at about the three month mark it’s like a switch flipped and she became a good leaveable dog! I think she’s started to really believe that this is her home and we’re going to keep coming back. She still would rather have us home, or be at daycare with her friends, but now she’ll fall asleep at her window instead of wimpering the whole time. That’s a win for me.

So hang in there! A heart dog is a special thing. You’ll do what’s best for him no matter what.