Roland MC-4 and MC-202 allow easy non 4/4 stuff.
OP1 endless, tombola, sketch all do too.
Roland SH-101/01a and JX3p all have freeform note entry.
Tenori On has a number of sequencing methods not tied to 4/4.
Older hardware sequencers such as Yamaha QX/QY, Roland various models.
Plus tons of others such as those already mentioned.
They are out there but 4/4, is it is fair to say, is the most widely implemented.
1 Like