Public nuisance in the protest context turns on precise particularisation: what exactly is said to have been obstructed, for how long, and with what effect on identifiable people. Cases are frequently won or lost on how well that detail was captured at the outset, long before anyone reaches a courtroom.
Our experience is that the contemporaneous record matters more than the eventual argument. Times, sequences, who said what and in what order, and any footage or audio, all decay quickly. Assembly rights are engaged from the first moment, and a Convention-compatible analysis is far easier to construct from a good record than from a reconstructed memory.
If you are facing a charge arising from a protest, the practical priority is to preserve everything and to write down the sequence while it is fresh. That is work we can help with immediately, and it is the work that most improves the position of whoever eventually argues the case.