Preemtive strike bugged?

[fambaa]

I was testing several Arche mods.
We all know Multitalented and Dangerous Ambush and Walk a Tightrope work.
Technique Manual also works, but its really weak, unless you have massive amounts of HP in the first place, the damage would do around 600 damage when you have 5K HP 1200 when you have around 10K HP and so on.
Now preemtive strike is supposed to do 8,5% on a target with full health

On an 800K hit that would be around an additional 70K damage.

Upon equipping the module it does not show an additional damage tick how it is displayed on technique manual, and the damage overall also is not higher, so I am pretty sure that it does not work.

Tested on Lepic with a single grenade and also his ultimate. The damage is exactly the same with or without.