Just a quick comment on this part. You could designate the walls on an intermediate level in a much quicker way.
Definitely. I was just demonstrating multiple principles by putting two different methods (corners only, or "all but one from the corners only[1]") in the same picture. Inefficiently. Same went for the "corner only" or "corner and one edge" of the "build along wall-top" example that followed. Best to stick to one
or the other, and not mix.
The advantage of doing corners-only (assuming full floor access, not wall-top) in the first stage is that they go straight to the front of the building queue (after everything currently 'in process' has happened, until you add something else at least...). You need only wait for the four completed corner constructions then paint down the edge-wall lines. (Or even sooner, if you see the builder(s) of adjacent corners standing on the perpendicular edges, allowing you to put down the required joining-edge wall-length with relative impunity against self-blocking jobs.)
The advantage in doing "all but one adjacent wall" is to get more wall-tops sorted, more quickly, in order to get the next level above properly walled-and-floored[3], or extend your overhangs further. And you could have particular wall-tops you'd like sooner than others, so set
their building definitions last, to be done 'first' (or nearly so, pending even
more constructions going on).
And then there's various hybrid[2] variations. Play with it, is what I'm saying. If you don't want to spend more time (paused) initially setting it up then you might need to spend a little more time tidying up, but you can play it vice-versa. A few key-presses either way. And as for total key-presses, are you counting the tap-tap-tap of extending each wall sideways/north-south?? Eats into the efficiency (although I'll allow you're still ahead on total key-presses, for each additional time I have to start a new wall, rather than just extend the current template that I'm laying down).
[1] Even
more efficient (in my schema!) with
.........
.#####+#.
.++++++#.
.#+++++#.
.#++X++#.
.#+++++#.
.#++++++.
.#+#####.
.........
...when enough is finished, there are just four single-wall gaps to fill.
[2]
Designate walls at '1', '2', '3', '4' (any order). Possibly wait a beat of unpaused game-time then designate corners at 'A', 'B', 'C', 'D' (again, internal order of this sequence not important). Corners will sit at the front of the queue (barring any edge walls that got seized upon in that beat) and then you can add the 'missing' walls in the gaps once the corners have been completed, even before the numeric-indicated lengths have been finished. Or possibly even started!
.........
.A1111+B.
.++++++2.
.4+++++2.
.4++X++2.
.4+++++2.
.4++++++.
.D+3333C.
.........
Yes that's
eight twelve total designations (eight at first, four more later on, compared to eight total for each of the "non-hybrid" versions from which this is derived, and four in your example) but it might let you get on with other things in the mean-time.
[3] Side view of construction...
#_##### "all but one corner-adjacent" set to be built on Z+1
_#######_ atop a completed ground-level floor
#####_# depending on what floors you have, you can switch the gap direction on the Z+2
####### even before you set this Z+1 gap to be filled....
_#######_