After chatting with the tech, I am strongly considering going manual with the PHII.
The current version of the PHII is the PH SuperFlush
Raritan PH SuperFlush Same PHII pump but on a newly designed base. It only uses sea water. However, there is one manual toilet that's designed to use onboard pressurized fresh water...the Raritan Fresh Head
FRESH_HEAD Promo Sheet
Expect a PHII will fill the holding tank much quicker than the Elegance.
It won't if you learn how to use the "dry" mode to do more than push the remaining bit of water out of the bowl. (Details are in my book...see link in my signature).
I'm not sure how your tech measured the space, but the household size bowl on both the PH SuperFlush and the Fresh Head is 2" longer front-back than the Elegance and combined width of the bowl and pump on both of 'em is 2" wider than the Elegance. You can check the dimensions for yourself in the literature for the links above and the one to the Elegance I posted earlier.
Peggie
"If you can't explain it to a six year old, you don't completely understand it yourself." --Albert Einstein