The Swiss QR code is just the vax certificate. That is part of the document check that goes into the SpTH QR code. You can do most of the application beforehand and it's honestly basically just hitting send and getting a qr code back. Takes 5 minutes and even less if you have the application prepared already. But I can't imagine any airline letting someone board without everything completed as per Timatic. You might not be one of the first on board but all in all seems like plenty of time to get it sorted.