I recently found the nicematrix package, and I am using it to for scripting.
Since my goal is to have a macro/environment which makes an augmented matrix (vertical line before the last column in my case), I was searching for a way to pass something like RRR|R as format string to pNiceMatrix.
Soon I figured out that this is not possible (right?) and found that the NiceArray environment would support this.
Since setting the parentheses is not a problem (I can specify this in my macro/environment declaration, thus later this is irrelevant),
I was wondering if I'd have any drawbacks by moving from pNiceMatrix to NiceArray?

gaussMatrixenvironment for now. I've got just one little problem with pgfkeys and nicematrix (new post https://tex.stackexchange.com/questions/548110/pgfkeys-and-nicematrix-calculate-with-pgfkeys-and-use-in-niceatrix-preamble) – atticus Jun 06 '20 at 16:42nicematrixone must writecinstead ofCin the preambles of the{pNiceArray}(but there is an option for backward compatibility). – F. Pantigny Jul 18 '20 at 21:12