Your problem seems to have been solved, but what I did once was make a fire charge. It may not be possible in BTW though as this was in vanilla.

I might be wrong, but wasn't using half blocks to prevent mob spawning removed in one of the previous updates to BTW.

It seems like zombies are now more willing to throw themselves into the sunlight; and I've seen a lot less skeletons and zombies going for a morning swim.