This guide was from I8, but I believe most of the information is accurate: F22Major's Guide to Powerboost.
From the list, I would tentatively say:
Infrigidate - Yes
Benumb - Yes
Sleet - Yes to the -def and slow, no to -resist
Heat Loss - Yes to the end drain and amount returned to the use, no to the +recovery
Smoke - Yes
Flash Arrow - Unsure, as this is unresistable.
Speed Boost - Run speed, yes. + Recovery, no.
Forge - Yes
Heat Exhaustion - Yes to the endurance drain.
Fortitude - yes
Recovery Aura - No
Regen Aura - No
Adrenalin Boost - No
Clear Mind - yes
Obviously Power Boosts boosts mezzes, shields, and so on. But what about the following:
- Infrigidate
- Benumb
- Sleet
- Heat Loss
- Smoke
- Flash Arrow
- The -Defense/-Recharge/-Speed in Earth/Ice/Gravity powers
- Speed Boost
- Transference
- Forge
- Heat Exhaustion
- Fortitude
- Recovery Aura
- Regen Aura
- Adrenalin Boost
- Clear Mind/Thaw/etc
Just curious because I'm trying to figure out which sets it blends well with and which it doesn't.