I would just say that in very tense situations where the exact details of a law very much matters, the difference between different legal systems might be worth some consideration.

That's a good point. My understanding was College of Policing gives professional guidance for all UK, but its bearing on Scotland & Northern Ireland may be looser.

British Naturists seem to think it's legal in all UK, Scotland & Northern Ireland follow similar policing practices (consider every case on its merits) & may take that document into consideration. They provide a summary mentioning the Scottish counterpart of the law you mentioned: their language look quite similar (similar purposes/conditions to qualify as offenses).

While the similarity in these laws is compelling, and naturists report they are policed in similar ways, case law might qualify their interpretation.

The rando's writing shown in the OP could mean anything, and if you follow the link to that post, you'll find a similar discussion to this one that links similar content.