I have also modified the LaserGRBL app for using it with 3D printer GCodes, and I have not noticed the differencies in quality between this two apps.
And really? GRBL is supporting 3D printer GCodes? Very nice! I don't knew that. I thinked it is not supporting this style of GCode and for 99% of users your request will be unusefull. But then, I think I will release a new version soon :)