lw, so i got a "sip2sim" eSIM from @aaisp... now my phone connects straight to whatever SIP server i configure (via VoLTE, not an app) instead of going through some awful telco services.
and as a bonus it can roam between EE and O2 so i get much better reception at home.
i'm glad they managed to "un-cancel" this service because it's pretty handy.