snare shy surprises me. Maybe shiny, open snares but well-blended are pretty difficult for anything to spot. Just my opinion. Snares generally require more depth to drown than front foot catches. I would also not be using offset jaws in a situation where catching an educated beaver was important.
Truly educated beaver, to me, mean that your presence wading out like that would ruin the chances at the set. Educated to me means they monitor your presence in their area, and it directly impacts their movements. They can't be that educated if pulling multiples off the same set. That's just my opinion and nobody knows but the trapper who is there.
I'm not some master. Usually when I have caught the last of a colony it is either on a dam break or a subtle set that is well away from all the commotion caused by catching the others. Like a very subtle crossover trail or a spot that looks like a possible crawl out.
Those beaver have to be coming from somewhere else, I would try looking for other spots to set.
Shiny is possible. Snares not as weathered as I like.
As far as wading out to the set it's more like wading by the set. The only time I touch ground is at the dam and levy which are past this particular set, and the pasture where I enter the flooded timber 100 yards away. It's definitely a unusual situation for me.