Not sure on a mac but on Windows machine the auto recovery file is in scratch directory. Should be labeled PS AutoRecovery.
Not a Mac expert, but there have been reports from PC users of AutoRecovery not working when the scratch disk is not the system volume.
You should experiment with the settings, and force failures by killing the Photoshop process to simulate crashes until you're confident it's autorecovering your document. Set the interval down to minimum to aid with the testing.
[...] I checked in the /private/var/folders/5v/_wq4wcgn73v2m_vmf9msxt400000gn/T/Cleanup At Startup/Photoshop Temp#### folder to see if anything is ever saved in there, and photoshop has not once saved a file in this temp directory.
No and Ps is not supposed to autosave the recovery files into that directory, as far as I know.
There is a "Scratch Disk" list of drive volumes in Ps Preferences > Performance. The list can be ordered by the user. The first enabled volume in that list when Ps is launched will contain my active auto-recovery folder.
If the boot volume is designated as primary scratch then the active auto-recovery folder is:
~/Library/Application Support/Adobe/Adobe Photoshop CS6/AutoRecover
If another volume is designated as primary scratch then the active auto-recovery folder is:
/Volumes/<volume name>/PSAutoRecover/<user name>