Well, for what it's worth I switched to Swisscom eSIM this week for my main contract. It was mostly painless, except that I am on a corporate plan and don't have access to our customer-portal, where the QR code which activates the eSIM is displayed. They sent it by email and walked me through it by phone (your physical SIM is deactivated the moment an eSIM is generated for the number). Why do this? I am on-call every couple of weeks and I'm going to put the on-call SIM of the on-call phone (a Pixel 3) into my XR, so I only have to carry one phone even when on-call. The on-call phone used to be a Galaxy Note 3 and I put that SIM via an adaptor into the phone that was the on-call phone before that, a trusty iPhone 3G (without S). Not sure if you can get an adaptor for the nano-SIMs, but I honestly wanted a phone with better battery life anyway... As a bonus, if I need to have a local SIM when on holiday, this is now possible, too.