Well there is a good secret that the companies who make all those Low Self Discharge NiMH batteries,
they do not say it to you.
Their specifications stands for environmental temperature of 20C Max !!
and another one... every batteries are mortal!
I love your humor... but the batteries are not that sensitive as you can probably think.
They are wild animals LOL .
The NiMH chargers are 20 years old technology, only for the batteries there is some room for improvements,
and due the fact that we have specific ranges in their capacity, there is no need for endless increments of the charging current.
The only excuse for having all those increments, are to own worthless dead cheap batteries, that you do not trust to charge them at the named specs.
Many old NiMH batteries that was made with low capacity, they are not here, they had become dust.
The AAA rechargeable have gain a tiny market segment, I use AAA only at my small Office desk LED light,
at the remote control of my Scorpio moto alarm, and today on my Agilent U1272A.
About AA, their capacity starts today from 2100mAh to 2850mAh and that's it.
There is no need for fancy chargers , but for healthy chargers.
And if you worry about temperature, it costs you nothing to add one small fan on your charger.
Especially if you live in hot climates.
Every NiMH it should retain 1.34V - 1.38V max as soon it removed from the charger and after of two hours cooling down period.
If you get higher voltage, the charger is damaged and overcharges the batteries.