OK ... I have a few 3S and 4S packs that have a dud cell ... but the other cells seem to hold and provide good power ... I agree that it's only a matter if time before they go west also .... but ....
There are times when a model is poorly designed / made that CoG is a problem and often requires weight up front.
Given that a 4S pack of similar capacity weighs significantly more than a similar 3S pack ... if the 4S is dud on one cell ... (I know you lose 1/4 mAh) ... maybe it can be used in that 3S model that needs nose weight.
Similarly the 3S with a dud cell in a 2S model.
I've looked at the packs with idea to cut out the dud cell ... but the foil tabs and soldering is welded or Hard soldered - not Soft soldered. I'm a bit reluctant to play about with cells and trust them to stay connected etc.
How many people modify or use such packs ? So far I use them for bench testing ... but thinking to use in less demanding models.