Botaim requires that the bot you're using it with uses the v.idealpitch and v.ideal_yaw data fields of the entity's entvars for storing its desired view angles (if you don't understand that sentence that's probably normal, it's programmer talking
) Perhaps GraveBot doesn't work that way, and that would be why that plugin can't be used with it. Talk with Ghoul, the author of that bot, to determine whether botaim2 can be used with it.