Plumbers typically aren't interested in doing small increments of work, and rightly so, without charging me a hefty flat fee per service call. The nature of my remodel is such that the plumbing, flooring, and the drywall must be done in small increments.
With a standard installation, I would have to punch a hole into an adjacent cabinet, saw a large hole for the 45 degree vent (I need to offset because I can't shoot straight through the sill plate without cutting a 1" deep channel down my rim joist), and punch a hole for the drain line through the bottom of the adjacent cabinet.
I could also run the trap arm through three cabinets and into a bearing wall, but I believe this wall sits directly on the main girder.
Going straight out the back of the sink base cabinet is not possible because the window sill is built up with horizontally stacked 2x4s to accommodate a window that was significantly shorter than the original rough opening. Even if we had cripples below the window instead of solid wood, I'm not sure I could get the vent up to 42" before going horizontal. I would also have to put a 2" hole through 2x4 king and jack studs, which would require some sort of Simpson tie reinforcement.
If I'm missing a really obvious solution, please let me know. I would prefer to keep all the pvc in one cabinet and drill a single hole in the cabinets.