I know this is hard to believe but there are Ponziani lines that even the super grandmasters are unaware of improvements. One such line recently played to a draw is 1. e4 e5 2. Nf3 Nc6 3. c3 d5 4. Qa4 Nf6.
I have published many such lines but there are still some I have not had the chance to publish--especially now that I am not part of Ponziani Power where much of the new analysis was published.
Super grandmasters will not use an opening as a surprise weapon unless they think it is sound.
There are some lines which have not been tested--quite a few lines--and I am in the process of testing some of these. [ wish I had a better chess engine and enough time]
To each-his own.