SMC says their lipos should be stored immed at 3.7v if they ar enot going to be used immed. They are the only company I'm aware of with this recommendation. Bryan from SMC used to be on here a lot and posted as much about this. They can puff if they're not stored correctly. the older gen SMCs were not this sensitive and didn't have this recommendation.
Does you charger not have a lipo storage function? If it does, it should just need to be told a voltage and it will do teh discharging. If no storage mode, use 0.5 - 1.0amp as this is what the typical storage mode discharge rate would be using a charger.