Trezor Safe 7. A couple of questions.

[dkbit98]

As far as I know, on the Trezor Model T and other models with an SD card slot, it's possible to update the firmware via SD card, you can even check the SHA256 of the binary.

That is true, you can update Trezor model T with an SD card, and I guess you could connect device to power bank as a battery source.
I didn't try how that works in real life, but there aer better options available if you are looking for true airgapped hardware wallet.
Bluetooth connection don't need internet connection and it can be used for sending data, so in theory they could come up with a way to update firmware on Trezor Safe 7 that way.

[SFR10]

As far as I know, on the Trezor Model T and other models with an SD card slot, it's possible to update the firmware via SD card, you can even check the SHA256 of the binary.

You're right that some other models & brands allow users to update firmware via SD card, but the last time I checked, the MicroSD card slot on Trezor Model T and Safe 5 devices only offered hardware encryption as an additional layer of protection.
^{- They did mention in the past that they might add more features & functions to it, but AFAIK, this is the only one for now.}

[Pmalek]

You're right that some other models & brands allow users to update firmware via SD card, but the last time I checked, the MicroSD card slot on Trezor Model T and Safe 5 devices only offered hardware encryption as an additional layer of protection.
^{- They did mention in the past that they might add more features & functions to it, but AFAIK, this is the only one for now.}

I tried to find any sources discussing alternative uses for the SD card slot except for microSD card encryption, but there doesn't seem to be any. Encrypting and decrypting the device with the secret is what it's used for. Model T has been available for many years, so they had plenty of time to add support for PSBTs over SD cards if they wanted to or saving and installing firmware that way. It doesn't seem to be a priority for them and perhaps they will never take the airgapped route.

[SFR10]

I tried to find any sources discussing alternative uses for the SD card slot except for microSD card encryption, but there doesn't seem to be any. Encrypting and decrypting the device with the secret is what it's used for. Model T has been available for many years, so they had plenty of time to add support for PSBTs over SD cards if they wanted to or saving and installing firmware that way. It doesn't seem to be a priority for them and perhaps they will never take the airgapped route.

I also didn't have any luck in finding the exact source that I was referring to ^{[it was either a response to someone on X or on their subreddit (I'm pretty sure it wasn't on their forum)]}, but I did manage to find something close to it: Upload firmware over SD card
^{- By the look of things, you're right (it no longer appears to be even a low-priority one).}