"That is, temperature is a side effect. It is not the desired behavior or the reason why you'd adjust a camber or toe setting"
Even with context, that does sound like you will NEVER set the cambers or toe to avoid tire heating, which is definiately not the case, unless you are hotlapping. I see you didn't mention endurance in your post, but you didn't mention that it does apply exclusively to hotlapping either.
I might be at fault for misunderstanding your post, but this is what came first into my mind after reading it.
Maybe I should have inserted the word "typically"...
Of course, if you can't ever get your tire temperatures within a basic operating range (that list on page one shows a range between 10-25 degrees centigrade) because it is cold out or it is midday in the desert, you make adjustments. If you're on a rough track and you notice that though you like your setup, it degrades and overheats the tires, you dial it back.
On a few hotlaps you can go to more extreme settings, because you only need to do a couple of laps. If you need to preserve tires over a long distance, that's what you focus your setup goals on. In F1 2013, all my setups were all about tire preservation, as it made the difference between option-prime-option, or option-prime-prime, on many tracks.
Considering most of us are hotlapping at 14:30 at 26 C with 100% full grip conditions, making specific setups to get to some ideal tire temperature (let alone a specific 5 degree difference between inner-mid-outer tire) as a core goal, rather than handling, carrying higher speed through a corner, greater top speed on a straight, etc, (where you could secondarily make adjustments if that results in excessive tire heating). seems/seemed a dead end to me.
That is, there are reasons, of course, why you'd want to make adjustments to handle tire temperatures - but surely you do that as a secondary step
after you dialed in how you'd like the car to feel?