Hi kimmo,
I agree that the objective lenses have been sliced, but why would they do that rather than just giving the lenses a wider baseline so that there's enough space for them to fit without slicing, like in every other binocular?
I think the answer might lie in the design choice to use exactly the same inline Schmidt-Pechan prism and IS mechanism for both the 30mm and the 42mm models. My guess is that the centers of the 30mm and 42mm objectives have the same baseline of perhaps 36-38mm so that they can both align with the fixed baseline of the prism/IS unit at the back of the unibox housing. Rotating rhomboid prisms behind the S-Ps then bring the eyepiece baseline up to match the range of human IPDs. The result is a very short baseline between the objective centers rather like a reverse Porro.
Why didn't they choose a single shared baseline wide enough for the 42s? My guess is that using the narrow baseline had the advantage of keeping the 30s from being too large and heavy and allowed the 42s to be unusually small and light. And, as you said, lopping off the edge of the objective lens is probably not going to do much optical damage at 16x.
Henry