So, in trying to be accommodating, I think I've made it harder on myself.
I sent my editor an email that wasn't too terribly specific about what I'm doing with the climax. I didn't want to just say, "I'm thinking Seth needs to push Kendall on the ground" because I'd like her to read the scene without having formed preconceived notions. Because, to me, it really sounds awful.
I asked what she'd like me to do: describe it in all more detail to her, send the scene as-is so she can get a feel for what I'm doing, or keep polishing.
And she said this: All of what you’re writing here makes a lot of sense to me. As for those revised climactic scenes, the logic of what you’re describing sounds good, it really does come down to what actually happens in the scenes themselves. I still do want to make sure that there’s a concrete active trigger in either/both the scene with Kendall and with Mom that clearly leads to his shift and ability to make some peace with Isaac’s death and feel like he’s allowed to move forward with his life—not just back and forth dialogue but something that occurs, something he almost does and stops himself, etc. – just something concrete. But I do think that it will be easier for me to tell you whether I feel like that’s there once the scenes are more fully polished and reading them in context of the rest of the ending, so my gut instinct here is for you to keep working on them a little longer and then send me the manuscript fully revised. Then at that point after I read it over, if I still feel like those climax scenes need work, we can focus just on those and go back and forth on them specifically.
That is exactly what I didn't want her to say. At least I can now feel free to move forward with my plan. At least I know my agent and one of my crit partners feel like it's working...