Charging NMH chemistry cells is one of the most challanging , challange is where to terminate charge.
Delta temperture - rise in cell temperature over given period of time period is a factor,
Anyway the charger I used Powersteam brand is real stuff, this company sells proven, relable chargers , sure they know what are they doing.
Powerstream charger will not damage cells for sure.
This Powerstream charger has equalization period and balancing stage,
but the most important : delta temp/delta time is accurate enough in my Powerstream charger - I checked this on Eplus cells.