The display on the Tesla web site only shows sport and ludicrous. They should really keep insane mode as a medium option. For no other reason (and it's a biggie) that it looks cool on the screen, especially if it said all three.
You'd think they'd keep Insane mode there too just for the joke factor but maybe it's too close to Ludicrous Mode to make it worthwhile.
It should have four or five settings. Start with Valet, then Mellow, then Normal, then Insane, then Ludicrous. And then just keep adding to the right.
You don't need a config option. It can all be controlled with your right foot (with the exception of valet).
Agreed that the driver is in full control and can limit the acceleration very easily when desired. It's more for the comic effect and maybe to terrorize your passengers a little. A comment from several first time passengers on P85D acceleration videos is, "It actually says Insane Mode!"