Correction on my last post:
The bulk of the work is still to come
.
I thought the grinders would be easy to install, and they are, relatively, but the process is by no means easy, particularly since you are playing with fire, water and heights at the same time...
I also just realized something else we can do to increase the efficiency of the trap: there's a lot of wasted volume in the trap itself, if we place concentric single wide scaffolds separated side to side by two and, where relevant, above below by two, it will effectively increase the surface area of the trap and provide more spawn points for the mobs...