Ignite caused by Fireball is missing AoE property

Ok, after some testing I'm pretty certain of this. As we all know, damage over time inherits secondary properties of the skill that inflicted it, and it works properly for bleeding, poison or viper stacks caused by native AoE attack skills or AoE component of melee splash. It also works for ignite when inflicted by skills like flameblast, detonate dead or AoE attack skills.

In all such cases, supporting the skill with concentrated effect will apply its damage multiplier twice, once for hit that caused the effect and the second time for DoT itself.

It was tested with a clean character, minimally geared and freshly respecced on left side of the tree to have only life, chance to ignite and elemental/spell/burning damage bonuses. Skills were linked only with chance to ignite gem and conc effect, nothing else, it was tested on captain aurelius in battlefront. Results are expressed in segments of his health bar with the most average no-conc result taken as 100 point baseline.

These were the numbers for flameblast without conc effect:
100
97
108
89
91
86

and with concentrated effect:
283
308
273
280
291
296

We can see the 1,66 multiplier is properly applied twice giving roughly 2,75 times greater total damage.

However, when we repeat the test with Fireball without conc effect:
100
112
88
106
96
98

And with concentrated effect:
176
138
184
147
142
155

The multiplier is obviously applied only once, from live observations I'd say it's to initial damage but not to ignite. Of course, it's possible I messed something up but it's probably still worth looking into.

Did a similar test with flameblast, data here, and it had the same results as Raic so I'm pretty sure its a bug. Curiosity bump!