I hate to say it, but going 10-across in Y will also provide greater differentiation for PEY, which will probably be a selling point that CX would use to promote it. Unfortunately, an 8-across PEY and 10-across Y layout seems to be where the industry is headed even for transpac now, with the newest 777 configs for NH, CI and AC all configured that way. And though they don't have PEY cabins, Y in AA is moving toward 10-across as well, and the rumor is that UAs 77Ws will also be configured that way.