While the physical connections might be easy enough to repair for a skilled technician with the right tools, if there is FileVault storage encryption (with or without the T2 chip), how recoverable is it if the logic board is toast? I'm not saying it isn't recoverable, I am just interested to know how or if it could be achieved.
100% recoverable in this situation, since FileVault encryption is not tied to a logic board, but simply requires a decryption key, which is accessed via password. (You can use FileVault to encrypt external disks, too, and they simply need a password to mount.) Since the OP knows their login, they can mount the disk on any Mac, or use it to boot any Mac compatible with the OS version installed on the disk.
T2 encryption is separate from FileVault, and is strictly for onboard SSDs which use the T2 as the SSD controller itself. Basically, T2 encryption is the hardware-level encryption, while FileVault is the filesystem-level encryption. (FileVault is aware of the T2 hardware encryption and won't bother layering software encryption on top. Since a T2-based SSD cannot be separated from its logic board except by desoldering the flash chips, there's no ordinary situation in which you'd be attempting to mount it on a Mac other than the one it was written on.)
OK thanks for the clarity, the FileVault sounds much like Bitlocker in that respect.
I believe so, with the caveat that I'm not much of a Windows expert. (Also, I should mention that what I described is the current version of FileVault, which is FileVault 2. The original FileVault 1 used in very old versions of Mac OS X worked entirely differently, merely moving a user's home folder (user directory) into an encrypted disk image.)
So if I am to understand you correctly, a failure of the T2 chip, practically speaking, renders the unit unrecoverable?
Yes. Exactly the same as in any other SSD with hardware encryption using a long key that's present only in the SSD controller.
It looks like the T2 chip, as well as for soldered in SSDs, is also used for the new Mac Pro modular (but proprietary) SSD modules, so two points of failure if a T2 failure is also fatal.
Oh! I didn't realize the new Mac Pro has modular SSDs! According to this report, the SSD module is married to the T2 on the logic board. It won't even POST without it present. Presumably, Apple has an internal utility to marry replacement parts, as they've had for other models (and iOS devices) for years.
Regardless, I don't see the T2 as being any more or less a point of failure than in any other SSD, since every SSD, by necessity, contains an SSD controller, and it can fail. And if it did, it presumably would take all the data with it.
What I love about Apple's ecosystem is that they REALLY, REALLY got backup and restore down PERFECTLY. Using Time Machine on a Mac means its backups are updated hourly. iCloud sync is usually real-time-ish. iCloud backups of iOS devices are performed daily, and local backups can be done manually. But whether it's a Mac backup from Time Machine or an iOS backup from iCloud or a local backup, when restoring to a new disk or new device, everything gets restored
perfectly. Only the very pickiest of copy-protected applications on the Mac may need a license reactivation. I think that the ability to recover from disaster by, in the absolute worst case, going to Apple and purchasing a new device, and be back up and running within a few hours, is an advantage that is not valued nearly enough by most people. So anyway, if one is actually using Time Machine, then a T2 failure would normally mean a loss of no more than 1h of work.