tl;dr: log collect —device
log collect --device lets you retrieve log archives that can be passed into log show --archive system_logs.logarchive with all the options you’re familiar with.
Use log collect --device to automatically guess the device you’re referring to.
log collect device-name="Maxs iPhone" or log collect device-udid=abcdefg to collect from a particular device.
log collect --output /your/path will save it to your specified file name or directory. If --output is not given, your output will be in the current directory as system_logs.logarchive.
Note: I occasionally get errors about log: failed to create archive: Device not configured (6) or log: failed to create archive: Connection reset by peer (54) but if I just rerun the command it’ll sometimes work 🤷🏾♀️