Mechanics Question - Chain

I have been working with an EK build based on Roth's Reach and Deadeye passives, but I don't notice the chains much. I am aware that EK cannot shotgun, but I want to know if I can shotgun with the chain projectiles.

e.g. with 3 mob, A B and C, A and B are hit by EK with chain +1, what are the possible scenarios with chain?
example 2: with same 3 mob, all 3 are hit by EK, what are the possible scenario with chain?
example 3: with a rare mob and 6 blue, all 7 are hit by EK killing all the blue, will all the chain then hit the rare mob, effectively shotgunning it?

P.S. what is the range of chained projectiles?

Chain is a bit of a wildcard, we know it prioritizes enemies that weren't already hit and that breakables are the lowest priority, also the distance may also be a factor. However, every target is processed individually so it may not turn out the way you expect.

For instance, in example 3 you will hit the closest enemy first and chain will retarget to another enemy. That enemy will most likely be hit sooner by the non-chained projectile because it used the shorter path and if that projectile kills it, the chained one will be wasted. Also, if an enemy was already targeted by a chained projectile it is less likely that the next chain from another enemy will target it.

The short answer is we got no idea, depends on the exact enemy placing, projectile speed and whatnot, it may be that only one chained projectile will hit the rare, maybe all of them, and maybe none. Due to the randomness and wasted chains, chaining will always perform worse in practice than we expect it to.

Thanks.
*insert disappointed emoji*