May I enquire, why isn't charging to 100% good for a battery?
I have an RX450h+ and a myenergi zappi and Octopus Intelligent Go.
During the day, when sunny, I charge to 100% from solar panels. My Lexus app tells me when the car has completed charging to 100%.
Overnight, I charge from the solar storage batteries and then if not enough juice available it switches to cheap rate (between 23:00ish - 05:00ish) from the grid. Again, my Lexus app tells me when the car has completed charging to 100%.
I don't appear to experience any problems and it all happens automatically.