Omni-vents works on everything. Sort of!

I always thought that omni-vents didn't work on biotics and generally wrote the ability off, but today I learned something. Omni-vents triggers off of any tech ability and reduces the cooldown of any kind of ability A) if you have more than one tech ability, or if you have only one tech ability and it is not equipped in the first ability slot. If you only have one tech ability equipped, and it is in the first ability slot, omni-vents will not trigger.

The more you know.