I really like this idea a lot ES.
The best split tones I have for any of the the 2 humbucker guitars in my collection is my '09 PRS DGT
The DGT's from the 1st few years all suffered from weak thin tones and low volume when the tone knob was engaged for the split tones.
The remedy to correct both issues, was to inst. a 1.1K resistor on the neck and a 2.2K resistor on the bridge.
After these mods were made, then the split tones sounded rounder and less anemic, and the volume drop was gone.