I think this is one reason they changed it into "half action" in OW

Fair point Theofonias. The point though was more to state that it is an offensive psychic power and you cant use two offensive powers at the same time. The bit about it negating an actual attack was me not cutting that part out!

However I would still disagree with multiple uses purely on a balance reason, Tabletop rules IIRC (at least in 5th ed) only said that no matter how many attacks in CC you get you can only make one of them a force weapon strike.

I agree that it would be really over powered if you did let people use it multiple times. However it's not a "Psychic Power" more so that it is an effect of the weapon that is reliant on a Focus Test (and a WP contest) and that was my only point of contention. It's the same reason why Librarians can't Smite someone and then chop them up with a sword, or Charge them, or shoot them: they are all Attack subtypes. So, with the subtype mechanic in mind the pulse effect wouldn't be affected since its own mechanic logically supersedes it.

Were it me, I'd let them at least have the Counter Attack. They would have to get through 3 tests in order to have it go off (Parry, -20 Attack, Focus Test) but of course I tend to run "heroic" games.