I don't think it will care which iOS browser you use. Your app would be invoked as a sheet instead of an app. It's different from a safari extension, but similar concept. Safari extensions (I believe) are invoked from the Safari share sheet, which I think is clunky and unintuitive. This approach would follow the same flow as today: click the SQRL login, followed by "do you want to open in ?" followed by your sheet. I'm not sure how CPS works so I can't comment on that. I will say that having to switch back to Safari is annoying, so if there's any possibility this could work, I think it's worth checking out.