Interesting!!
The 900?A stretched 72?Wow!!
I don't know would that physically work though. The 72 is a stretched version of the 42. The 42 is perfectly balanced and the stretching of the 72 throws it off slightly,making for interesting load sheets.
I think they would have to completely re-design the structure to make it work but it would be fantastic to see a 90 seat ATR fly.
CP.