I use that exact rule in the leagues I am commissioner of, from the 3rd round onward. In rounds 1 and 2, you have to wait for your time slot. After that, as stated above, as soon as the previous owner makes a legal pick, the next owner may pick. Even if there are missed picks on the board.
It's transparent and I reiterate it every single draft so no one should ever be confused about it. My rationale is simple: make your picks on time, or use proxies. If you can't be bothered to do either of those, I see no reason that other owners should have to wait for you. I prioritize the good of the league over the good for any one owner.
Yes - sometimes life gets in the way. As commissioner, I always make it known to my fellow owners that if they know in advance that they will be offline for a prolonged period, I am happy to pick for them if needed.
When crazy stuff happens such that an owner is unexpectedly offline, yeah, that's a tough break. But WIS ain't that important in the big scheme of things. You miss a pick, you miss a pick.