[pilif]

> to avoid some of the BSDisms on macOS

to be fair, you should probably call the GNU behaviour "GNUisms". The BSD behaviour is the historical POSIX behaviour. The GNU behaviour is, in a twisted sense, the result of embrace, extend and extinguish by the GNU people :-)

[LukeShu]

With a couple of small exceptions[1], the GNU behavior is also the historical POSIX behavior; the differences that will be jarring are where both BSD and GNU implement things that aren't in POSIX. Yes, the GNU behavior is GNUisms, but the BSD behavior is also BSDisms.

[1]: The most notable thing is that GNU generally allows flags to come before or after non-flag arguments, where POSIX requires them to come before.