If you've asked me a few years ago I would have dismissed buying any >4.5 inch screen phone immediately but I have got used to seeing the larger screens. The larger phones already have a significant market share and the trend is still up.
https://techcrunch.com/2017/05/31/ph...e-the-phuture/
I think it will depend on the overall look and thickness how it will be perceived.
On my Pandora that has a 5 inch screen with a large bezel and a lot bulkier than the chenphone will be, I don't have any problem thumb typing for long periods of time so I don't see any issue there. More important will be the weight distribution - keyboard vs screen and that seemed to be the problem with TOHKBD.