It's always a tradeoff between the best possible way to store a battery, and convenience.
Two years and done is a good way to go, if you are doing a daily commute grind. You need to make it to work, you don't need to worry all the way every day, so a new battery every two years is a good way to go. The old pack may still be somewhat usable for the 3rd or 4th year, but it will be shorter capacity, and sag a lot under load. So you can still use it occasionally, adding range for a really long ride.
My own pattern is buy at least 10 ah every year or so. I end up with a huge total capacity for the longer rides I like to do, but always have at least one pack that is pretty fresh. That fresher pack gets the most use, and I keep it at 90% charged. I can hop on it as is, or quickly bring it up to 100%.
The others store for much longer periods, sometimes months, at more or less half charge. If the battery has a bms, then I like to store a bit fuller, but more like 75%. this is because a bms will slowly drain some cells in storage. Unplug a bms for really long storage. I don't worry about balance at half charge. Why?
Because a ruined cell will self discharge anyway, no matter what you do. It will drain itself no matter where it started out. And if the cell is not ruined, it won't self discharge, and it will remain full enough, though it may still need a balance charge on wake up.
