I think at this point if you want to optimize the process, you need to pick a different approach and not rely on a photograph of a wall.
I agree, there definitely needs to be other challenges put toward what I'm doing but that's all I have at the moment. In this instance I consider it valid.
There is still some slight unevenness in the wall in both images
No, I disagree, I'm the one that was looking at it. The gradation in the tonality of the walls as they progress toward the corner is accurate in both negatives. I used the spot meter to confirm what my eyes were telling me, which was that there is a luminance difference moving toward the corner, the spot meter agreed with my eyes. From the camera position, I took a reading on the wall, about a foot or so above the chair next to the curtain, then at halfway between the curtain and the corner, then at the corner. I took a reading on the right edge at the wall, at the same level, then halfway, then at the corner. In both instances each reading from the edge toward the corner differed by being 1/3 stop lower in luminance, with the corner being the lowest spot. I, the one who was looking at it, simply cannot argue with the results on these two negatives in how the walls are rendered. If you're now going to suggest that I don't know what I am seeing in front of me, well now, surely not.
You are quite right to point out the need to be cautious in what is viewed a success. I can see how my remarks above would seem to not convey that idea, my remarks are limited to just those negatives for just that scene. You can bet I'm going to challenge my own post above with different pictorial images with different continuous tone areas and using that tray method. It's not looking like I will ever use tray development routinely at all, especially if the tank is doing a fine job for me. But I've wanted to try tray development to see what I could learn, to see if I was missing out on something it may offer that is better than what I'm currently doing, so far, I'm not seeing it. But it has been interesting and edifying.