Yes, Erik, the prop delays, worst-case, are long, but he's dealing with switches here ... switches that may change only once in the life of the product (it wasn't stated). The boss probably got a good deal on those shift registers, and has a barrel-full in the stock room.

OTOH, if his intention is to buffer them with Schmidt triggers, it doesn't matter anyway, does it? He's not in a hurry, since he's probably clocking the PISO register from firmware, else he'd use faster PISO registers, e.g. 'HCT165, and the HCT Schmidt triggers provide the input protection. It would seem the bases are covered.

It all depends on how fast he intends to clock the PISO registers.

RE