I have looked at a few topics here aswell as Apple support but I am still unclear whether what I wish to do is possible.
I have an Iphone SE 2022 running IOS 26. I am on 2D with an esim.
Normally heading off to Oz (for example) requires that air-plane mode be on to ensure there are no roaming charges. When connected to a WIFI network wifi calling works fine with air-plane mode on and wifi on. However this means I can only receive calls and texts while connected to a wifi network which usually means evenings in accommodation or from time to time when a wifi network can be connected to.
I am wondering whether a travel esim will allow me to have wifi calling on seemlessly 24/7 while overseas. This would require all data to go through the travel esim, but the 2D esim would need to be active to allow calls to be made as if I am wifi-connected. Can I set airplane-mode only for the 2D esim but use wifi calling via the travel esim (which connects to a local cellular data service)?



