Actually, all SA390/400-type drives I've seen
(which are nominally limited
to 35 tracks) can step to a 36th track without any difficulties, and
most can go to the 37th. The "36th track" trick was very common on
Apple ]['s, both for copy protection and for general use.
Was an early hack I used as it added another 5k of storage on those tight
SSSD sa400s.
I've noticed that most decent data forensics tools
(Anadisk, etc.) will
go the the 81st track on a 80-track drive, though I've never seen a
floppy that actually had data out there.
I've tried it and it works on both 5.25 and even 3.5". One use I had
was to put a duplicate directory there where it was not normally
accessable except with a tool.
Allison