Byepass is a passwordless access system.
When I requested a log in to developer area (which I assume is how any Byepass login would work) on my mobile, I thought it had not worked and having tried it on my desktop I now realize what had happened.
I did not realize that the original screen I had logged into had changed to show the contents because the mobile window/ screen telling me that the challenge had worked was blocking it (even though it was still there).
I presume that your use-case is that a user would request login on a desktop and then authorize the email challenge on their mobile. In this case it would work perfectly as the the original descktop login request would be showing logged in content.
very low friction for the user, very intuitive for the developer
Its confusing in that the challenge result window/screen is redundent and you have to go back to the original window/screen esp on mobile