I think asus 9z should be in the same comfortable form factor as zenfone 8 with some minor tweak like ° dimensity 9000 with advance vapour cooling with addition of graphene layers to keep the processor cool for stable performance . ° 4000 mah battery pack should be split in 2 part by which it enable 60w fast charging(mendatory). °As per camera .omnivision OV 50A 50mp as ultrawide .Sony 766 50mp or any other custom sensor with collaboration with sony as main shooter with lostless zoom capablities. ° and headphone jack with dedicated dac.
As for 9 ultra ° 6.7 inch screen size 120hz refresh rate ° bigger battery at least 5500mah ° same ultrawide and main sensor for lower cost and additional 5x optical zoom lens with ois if periscope is possible then it will be fantastic. Samsung gn2 sensor will be great. ° and an earphone jack with dedicated dac is mendatory in both the phones. ° and an integrated stylus if im not asking much for designing or other task. Share your views . . .