Hmm, that's a tough one. You know how generally anti-kibble I am, but I admit that there are times when it's not so cut-and-dried. I can only tell you what I would do, and that's based on my limited perspective of your particular situation. What if you were to cut out all the kibble but weigh Jasper frequently to keep track of anymore changes? It's possible that his weight is just balancing out and will level off, and hopefully his appetite will pick up the slack. Can you sneak him more food at quieter times periodically? If he still continues to lose weight, then maybe a small amount of kibble ain't so bad (Innova EVO is the highest in calories at 612/cup), as long as he still gets predominantly wet. Could it be that he also needs more enticement with the canned? Something like Real Food Toppers crumbled on top, or some tuna juice or parmesan cheese? A pinch of nutritional yeast powder also works well.
Jasper sounds like such a sweet, sensitive soul. I totally understand how frustrating it can be when kitties don't eat the way you want them to. Early on in Aztec's diabetes, he had some serious appetite issues and my whole life revolved around trying to get enough food in him. I would sit beside him while he ate and hold my breath until he was done. If the phone rang or hubby walked in and disturbed us, that was it, Aztec would walk away and I would literally start crying. Entirely different story today! Now he's a little pig and I'm having trouble getting his weight down (which is complicated by being diabetic).
Let me know how it goes, and give that handsome cat of yours some extra chin scritches for me.
"To close your eyes will not ease another's pain." ~ Chinese Proverb
“We must not refuse to see with our eyes what they must endure with their bodies.” ~ Gretchen Wyler