For 0.10.5, I propose this backroute fix for Division of Labor. It's a single triangle added in the background, see screenshot.
This prevents a lucky right-facing basher from cancelling directly before the basher reaches the diagonal shaft. Now, the basher will see enough pixels that the basher decides to continue. The diagonal shaft will still open from bashing and then kill left-facing walkers.
Edit: Earmarking this fix for 0.10.5. I didn't get feedback, but it seems sensible to me. The terrain looks nice and the fix prevents my backroute. If you don't want it, let me know, and I'll remove it in 0.10.6 or beyond.
-- Simon