I agree... The engineers are very smart... and getting you to buy a new battery in a few years is great for Bosch. But if they were working for the end user, all chargers would come with a variable charge option.I charge my Bosch gen 2 battery when i get home from work. It stays on the charger overnight and shuts off on its own. Just my opinion, the minor gains in battery life are not worth the effort of trying to outsmart the battery management system. The engineers who designed this system have far more experience and education than I do. I paid for their expertise and manufacturing allowing me to just enjoy the ride without worrying about it.
Understand that no one is trying to be smarter than the engineers or the BMS...it's just how lithium batteries work. Period.
All depending on how much of your battery capacity you need per ride and how much you understand the benefits of implementing a strategy should govern how you approach this. It's really not difficult or time consuming and I can charge my battery to 80% (or any other %) with the same ease as you charge to 100%.
But you do make a good point in that if it detracts from your pleasure of ownership... Then it is not worth any effort at all.