I can tell you from firsthand experience that any shoe/sandal that you want to be able to do double duty IF needed, needs to be able to be secured with more than a simple Velcro strap.
Sand/mud will get into that Velcro and you step into mud and when you pull up, your barefooted.
This trip I almost pulled myself out of my portage shoes 2x on the portage into Ram lk.
Part of the portage was thru that gray/clay muck that looks like something a sculpture would use.
It's not only stickier than the typical black/brown muck, at depth, it's a shoe sucking vacuum.
I even tied my portage shoe laces and used that lace-lock I'm so fond of, but even with that double protection I had to stand on one leg and wiggle the stuck foot until I broke the suction.
Not an easy task wearing a heavy pack/canoe.
I learned that the hard way.