Hi,

G-code IS an industry Standard: it was defined by NIST after much industry discussion (and some compromises).
In practice that is not correct. Yes there is a defined standard but few pay it any mind, its certainly not binding. To whit: it seems every machine requires its own post, ie the Gcode for each is
subtly different.

Ideally Gcode would be portable, in practice it is not.

Craig