I know how it is with a CRF cat - you want them to get all the calories they will eat! Milo was very picky as well, he'd love a certain wet food one day, and hate it the next.
There is something you could do with the egg which would make it better for Dusty. Leave the yolk raw, but cook the egg white. Cooked egg white is very low in phosphorus, which is a huge plus for a CRF cat, and will make the whole meal be lower in phosphorus.
http://www.cornucopia.org/organic-egg-scorecard/ has an "egg scoreboard" rating farms on the conditions their chickens are kept in, if you are concerned about that.
http://feline-nutrition.org/health/s...ken-or-the-egg is another interesting article,
http://feline-nutrition.org/answers/...a-raw-egg-yolk is another article on the same site, that focuses on the nutrients in egg yolks as well as why it is generally best to cook the white for any cat if they are eating eggs frequently. I don't know if you are worried about any of that though - so just ignore that paragraph if you want.
Do you give Dusty any B12? I learned about giving that after Milo passed away, however, many people with CRF cats said that it does help a lot. It also greatly helped with Rajah, though he didn't have CRF.
http://www.ibdkitties.net/B12.html is an article about the importance of B12, and
http://www.ibdkitties.net/Supplements.html has a list of some good brands of B12, as not all brands are created equally.
http://www.felinecrf.org/canned_food_usa.htm#canned_usa is a food chart with phosphorus amounts. I tried to keep under 1.00 phosphorus for Milo, though with how picky he was, sometimes I would use ones over that, and just add a phosphorus binder.
http://www.felinecrf.org/canned_food_usa.htm#baby_foods is a list of different baby foods that are low in phosphorus. Baby food is high in calories, and cats typically love it - two important things for CRF cats!
Milo was always the most hungry right after I gave him sub-q fluids. I don't know why, but feeding him after that typically worked the best. That may be something worth trying for Dusty, if you haven't yet.
He also loved the "Holistic Select Transition Solution" - I would sprinkle a small amount on each of his meals. It also seemed to make him a bit less nauseous. On days that he was nauseous, I also gave him some Slippery Elm Bark,
http://www.littlebigcat.com/health/slippery-elm/ has information about that.
Your Cat: Simple Secrets to a Longer, Stronger Life by Elizabeth Hodgkins, DVM has a chapter about CRF cats. If you haven't read that, it is very helpful, or at least was to me!
I'm sorry if a lot of this is stuff you already know, but even if it is, maybe it will be helpful to someone else.