I suppose this is really about Latin, but since there is no Latin SE an answer using modern Italian would be welcome.
In the days of my youth we had a Latin teacher who used the phrase nota benissime when he wanted us to take extra special notice. I may have misremembered the phrase, and in any case it may not be proper Latin. I would be interested to know what if any the proper Italian would be (bonus points if you can provide the Latin as well).
Specifically, if nota bene means note well what would be the phrases for note very well and note as well as you possibly could? I would only ever be using these phrases to English speakers (physics students!) in a tongue in cheek context so there is no need to strive for great precision.