Hello
Here is my operator's reply:
To change SIM to eSIM:
To change SIM to eSIM from abroad, you'll need to be connected to a French VPN at the time of the change.
No problem, I'm already on eSIM.
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For the iPhone XS transfer to the new one: fast transfer activated with my operator: Yes of course, the transfer is a local stream. No worries about localization for that
Did I forget anything? In fact I have no problem doing everything on the spot and even a trade in to get $100 back from my old one.
Interesting reply. I'm not sure the iPhone actually channels eSIM activation packets through VPN (just like it doesn't send iMessage or Facetime through VPN). I've never tried to trace those packets so I can't say for sure, but it's worth a try I'd say. Just make sure you have a backup plan if it ends up not working.
Also, these things apply no matter if you're switching from physical SIM to eSIM, or swapping an eSIM to a new device: it's still a new eSIM activation as far as the operator is concerned (but customer care agents don't know that).
Source: I work for a mobile operator myself.
