Actually, Musk just recently bought into a biolab firm that was looking exclusively into doing just this. Expect an announcement in the next few months.
After almost 90 minutes on the phone, and being transferred SEVEN times, I was able to get Boost activated on eSIM #2 on my Pixel 10 XL.
So far I've been on AT&T 100% of the time, no T-Mobile, even in areas where T-Mobile is stronger, and no native Dish.
Outside on the very edge of my property I can get a faint AT&T signal. It looks like Boost will connect to b14, I saw it on my way home from work, if nothing else is available, but even if there is a sliver of b12 or 66 it will latch on to those first. Which makes sense.