But he has an off-grid cabin on this one, so he probably would like to figure it out.... or yes check out a more productive lake in that area if Wollaston continues to be a bust.
I used to go to a hunt camp on a lake in that same general area. The bathymetry was probably similar, it was a very deep lake in the middle, over a hundred feet deep. The Ministry used to stock it with trout - first rainbows, and then speckles, and in good numbers for the surface area of the lake. It was nearly impossible to catch those trout, and it took me probably a decade to figure out why. There was so much forage in the lake (mostly minnows) that the trout had their fill any time they felt like eating. Every trout we caught was round like a football. So anyways what I did was jig very aggressively for them, both open water and ice season, and that seemed to attract at least a few fat trout.
It may be that Wollaston Lake is also very fertile, with a huge forage base. One way to test this theory would be to put out a few minow traps (if legal in that FMZ) and if you haul in a trap full of minnows after a couple hours soak, there is possibly the answer to the question.
But how to catch fish that are already stuffed like piggies, I do not know the answer to that question. I would tend to go reallly aggressive with presentations, based on where the graph tells me there are at least some fish. I will be interested to hear what happens here.
Doug