> It seems to me that making nph use a different style for something so > fundamental might be a problem
The issue is that with use of commas Nim developers can easily make mistakes, introduce ambiguity without realizing it. By use of semicolons `nph` forces a developer to consider ambiguities they may not have recognized previously. A higher bar would be for for `nph` to do it's best to sort out ambiguities and make best-effort changes: leaving/putting `,` where it works and `;` where it doesn't. Personally, I prefer to use `,` wherever it's not ambiguous, but I've definitely made mistakes in that regard.