We’ve been trying to consolidate laptop pull reports to this thread: BLF Community Battery Pulls Overview Thread (Laptop packs and Tool Packs)
As for how low to go before pitching a cell. My personal limit is ~2V for pack pulls. Other people pitch cells that have dropped below manufacturer discharge cut-off specs, typically ~2.8v. I think that is overly cautious for cells coming out of laptop packs.
A properly functioning laptop pack will prevent overdischarge under load, so if cells coming out of a pack have a voltage lower than 3.0v, it is probably because of slow self-discharge. The charge management in laptops/laptop packs typically allows recharging of cells below the cutoff voltage, but limit the current to a few hundred mA until cell voltage gets back to 3v. The Opus charger behaves similarly, as do, I believe, the TP4056/7 IC used in a lot of cheap power banks and charging boards. The IC used in the latest Miller ML-102 also is supposed to implement pre-charging, but I haven’t tested it.
Battery University suggests pitching cells that have been at or below 1.5V for more than a week.