chloyster FWIW, On my Pixel7Pro with GOS I switched to Tmobile from Verizon. Physical SIM slot was damaged, so I had to do esim in Tmobile store(s). E-sim download never worked for me. Quickly flashed to PixelOS, loaded esim instantly, then flashed back to GOS.
My mobile carrier obviously knows who I am. Never was a realistic concern for me. I also use sandboxed Google Play Services, so they know who I am too.
On my Pixel10Pro, I did not even attempt to transfer esim from P7Pro to P10Pro using GOS. I did it easily from home with stock PixelOS, then flashed to GOS.
Working well. Hiccups with USB port and address book noted by others also affected me -- but using GOS full time. Grateful to the GOS devs!!!