I bought an EQC over a year go and received no advice re charging %'s, and see nothing in the cars charging app to suggest likewise other than the 'option' to restrict the upper limits, I wondered what that was about!
I did see an article however that suggested it was the rate of charge which stressed the batteries most, with the higher rates (and associated heat) causing the longer term degradation of the battery (i.e. the more 'quick' charges the shorter the battery life), however there does not seem to be any clear advice on what is best way (or worst) to treat your battery, as the car has no limits and an eight year battery warranty you have to assume that anything goes!
I see many comments re the inconvenience of charging an EV, do remember that it can be charged via a normal 13Amp plug (recovers about 6 miles an hour) and as most cars sit idle either overnight or at a workplace either or both could be charging opportunities. Many employers overlook that a normal external socket would suffice and use the excuse of the cost of installing fast chargers as an out, slow chargers could be more suitable as there would not be a need to shuffle cars on and off fast chargers to service all, and as above may actually be best for the battery life, but then who knows?