5G on Dual Sim is a useful update, prior to this it was only possible to have 5G on one of the accounts (The hardware SIM, I think was the default not the eSIM)
I had resigned to thinking they got screwed with bad hardware from qualcomm
ehhhh there was a lot of uncertainty around that. they just said a future update and it wasn't on time.
I had my doubts and other people had their doubts, dual sim modes have been neglected for some time and there are still several limitations in iOS that make it seem like its not much of a priority.
until the last few incremental updates you can tell from Apple's own communications on their forums that they thought of Dual Sim as more of a temporary traveller's use case, with them popping in a local sim card in different countries here and there. As opposed to someone that doesn't want to bother with two phones (or a handicapped VoIP number that also wouldn't have an iCloud account) and just always has two numbers in the same country. They are catching on, but the skepticism is there and they are incrementally fixing it successfully.
> 5G Auto: Enables Smart Data mode. When 5G speeds don’t provide a noticeably better experience, your iPhone automatically switches to LTE, saving battery life.
Having used an iPhone 12 in an area with 5G service, I haven’t yet noticed the phone reporting LTE speeds, but given the way the statement above is worded (‘noticeably better’ is doing a lot of heavy lifting), I wouldn’t be surprised if the phone is mostly on LTE when it’s sitting idle or when I’m doing something like web browsing or music streaming that’s otherwise well within the capabilities of an LTE network.