Thank you so much for that. It helps quite a bit, and I managed to replicate what you did. However, this poses one more new issue I haven't been able to solve after a lot of experimenting:
Let's assume my stock is a rectangular piece of wood, and I want to create a 45 degree angle that goes from the base of the stock up to the surface, exactly as in the screenshot in my original post. I can't exactly use a Parallel operation with default settings and have my bit cut right through the wood from the surface to the base right from the first pass on a 45 degree slope, as that would attempt to chew off way too much wood in one shot. I assume I need to do it in increments so I can take a way a little bit of the wood at a time. So I experimented with "Axial Offset Passes", which is much like "Multiple Depths" for contours. However, although I can do several stepdowns, it seems that the toolpath is quite inefficient, as it spends a considerable amount of time (during the initial stepdowns) cutting through mid air, as can be seen in the new screenshot (side view). Is there a way to skip all this "air time" and maximize contact with the wood? Or do I simply need to slow down the bit considerably?