I did that too, with my 2013. You set the timer for 80%, but then disable the 80% limit in the global settings for the car. That way when the timer is overridden the car can charge to 100%. It's called, IIRC, "Long Life Mode" in the global settings, and you disable it. If you then set the charge timer to start and stop at the exact same time every day, with the 80% limit enabled for the timer, you can charge to 80% without having to keep setting the timer, and charge to 100% just by pressing the Timer override.
Brilliant Silver 2021 Leaf SV40 W/ Pro Pilot & Protection
2009 Vectrix VX-1 W/18 Leaf modules, & 2 lithium E-bicycles.
BAFX OBDII Dongle
PLEASE don't PM me with Leaf questions. Just post in the topic that seems most appropriate.