Ok, I'm with you on the first point. usage particulars dictate battery needs. But still, why not maximize your per-battery-vapage? And we both know that not all "2500mah's" are created equal...
Your second point confuses me somewhat. I realize that the IPVmini's input has nothing whatever to do with its output, but you're not suggesting that we can safely use a sub-13 amp battery in them, are you? Because what I know is this :
1) Watts In = Watts Out + Watts Used by Chip .
and
2) All batteries Sag Under Load
so
The IPVmini at times may actually need to draw 13A from its battery in order to output a mere ~7.8A which is why I'm anxiously awaiting the arrival of newer batteries onto the retail market like the mythical Samsung 30Q, which at 3000mah and 15A looks to be a winner for the IPVmini crowd.
Definitely NOT recommending using lower rated batteries for just those reasons. Battery sag increases as the battery is depleted do high Drain is a much safer option.
*that said, My only vapes at 7w/8w on an IPV mini and does use the panasonic CGR18650CH batteries.(Shhh)
I have not been convinced Higher Mah and High drain go together quite yet.
I'm using the Samsung 25R's in 3 of mine and MNKE's in another.
Both Mods in discussion have approx. 93% efficiency and I am hard pressed to believe the low input number on the Cloupor mini as both of mine out perform both of my IVP mini's at 30W and drain the batteries a bit faster.
Just my observation.