The new pool design looks great.
I didn't realize that screening the existing covered porch was something you were considering. The original design does not work at all with that in mind.

I'll give you a little insight to my thought on the new design.
Have the builder drop your waterfall flanks to weeping rock level and let the one on the right slip in slightly below the level of the spa coping.
I find that moss rocks placed over the top of a 12" raised spa like they have the drawing makes that particular rock and those adjacent to it look to top heavy.

just my .02

See ya,
Kelly