I think you may find a number of existing threads on this topic. They don't necessarily provide consistently helpful answers to your question, though.
My view is that what Fiat app and dash readings report as 100% is some way short of the true maximum capacity of the battery thus charging to 100% might not be harmful.
Nevertheless, my habit is to charge my La Prima (now over 3 years old) overnight to a level of charge sufficient to do the mileage which I anticipate doing the following day. Most nights I will charge to 60% sometimes more.
So I will only charge to 100% if I'm expecting to do 130 or more miles the following day. For info, I am getting ~3.8 miles / kWh in winter and ~4.1 in summer. Taking the effective capacity as 37kWh that equates to 140 or 150 miles.
I rarely let the battery go below 20%.
I have used a public charger only a handful of times in the life of the car as I have solar panels and an intelligent charger capable of 7kW at home.
My charging arrangements allow me to define what charge level I require by the morning and to stop charging when that is reached. I make use of Home Assistant for this. Happy to provide full details if of interest.
