399
Article: I switched to eSIM in 2025, and I am full of regret
(arstechnica.com)
This is a most excellent place for technology news and articles.
You don't need a carrier app. The phone OS asks the carrier network for activation and pulls the esim. I've done this several times in lineageos and grapheneos.
It does require some Google service related functionality though I believe so may not work without gapps (may work with microg and graphenos has its own handling as you said).