auto targeting unit with shield

[Thunderbolt]

from what I can see towers, or at least AOE towers, prefer to shoot on a group of creeps rather than on single ones running at the front. however, when creeps approach the end of tower range towers tend to shift focus and target that creep before it can get out of range. at least when the tower calculates that it can still kill that creep. is that right?

the problem here is with creeps with the shield ability. if that ability triggers when they reach the end of the tower radius then this shifting of focus wont work any more and these creeps will cause leaking. 

Id like to see the shift of focus on these creeps with shield by towers changed a bit. it would be useful that the shift of focus on such creeps already happens when the towers calculates that it can kill that units 2 seconds (2 seconds before the last projectile will hit!) before it reaches the end of tower radius.that way this problem could be solved.

[Karawasa]

The default targeting behavior is closest creep. Tower will then lock onto that creep until it dies or goes out of range. Certain towers override this behavior such as Impulse, Gold etc.. But there is no override behavior for AOE towers.

As far as the suggestion, Shield is intentionally annoying for AOE. Single target, and especially long range single target, are your counters to shield.