I'd say that the EV-100 install is a straight-forward thing. No tricky gotchas. The manual is fine and if you search this forum, there are many threads offering advice.
My advice is - plan it well, before starting the install. E.g measure distances to make sure that you have enough SeaTalkNG cables to connect things around, and decide where you want all the components installed.
The EV-100 does not require any calibration, but it does require set-up (e.g. setting the value for end to end (stop to stop) turn.
It took me 3 half days to install and I am not overly handy with DIY. And by installing yourself you know how and where things were put there. No future surprises.
Every boat is different, but in my case the biggest challenge was to feed the cables through the pedestal guard. You have to make sure that you don't introduce a source of new leaks.