It is very interesting that you say that. I have been talking to John Lauer recently about trying to jog with GRBL (i'm working on a jog dial and interface for the shapeoko) and how there is no way to wipe commands from the buffer. He brought up that he had heard that GRBL was simply as far as it could go and that features like a wipe couldn't be added because there was no room (I went and begged for it anyway - even offering pizza to someone who puts it into the mainline).Rarely you hear of a core feature being rejected for lack of memory.
Anyhow, I see your point. And perhaps it wouldn't be as disruptive as I imagine. I guess I'm just excited by the possibility of GRBL and the gcode sender not having to actually stream the code constantly and deal with the tiny buffer if the file could be completely downloaded to RAM. Maybe that's not as big of a deal as I imagine. Also, having recently been told that the arduino was just not powerful enough to get something that I need, I guess I feel like if that is true, the community would need to take the next step hardware wise.