TL;DRA visual connection between walls and cliffs to make sure you (or bugs) can't walk past it.
What ?Just started up a new game to see what has changed in the recent half a year or so. I'm still using cliffs to aid in my defence. No need to waste more stone and turrets to defend some areas is nice. What isn't nice is that often whenI build a wall adjacent to a cliff, there's a gap. and I want this wall to be solid so every time I walk into the gap just to make 100% sure that the gap is only visual and not an actual gap.
My suggestion would be to make the cliff and wall connect in some way, to show that there's no way bugs (or you) can get through. See also the two attachments for examples.