Yeah you can use multiple toggles, however, your way of thinking is too narrow minded.
Code:
local onLoad = function()
ProbablyEngine.toggle.create('toggleID1', 'Interface\\Icons\\some_icon_nameA', 'Toggle NameA', 'Toggle DescriptionA')
ProbablyEngine.toggle.create('toggleID2', 'Interface\\Icons\\some_icon_nameA', 'Toggle NameA', 'Toggle DescriptionA')
ProbablyEngine.toggle.create('toggleID3', 'Interface\\Icons\\some_icon_nameA', 'Toggle NameA', 'Toggle DescriptionA')
ProbablyEngine.toggle.create('toggleID4', 'Interface\\Icons\\some_icon_nameA', 'Toggle NameA', 'Toggle DescriptionA')
ProbablyEngine.toggle.create('toggleID5', 'Interface\\Icons\\some_icon_nameA', 'Toggle NameA', 'Toggle DescriptionA')
ProbablyEngine.toggle.create('toggleID6', 'Interface\\Icons\\some_icon_nameA', 'Toggle NameA', 'Toggle DescriptionA')
ProbablyEngine.toggle.create('toggleID7', 'Interface\\Icons\\some_icon_nameA', 'Toggle NameA', 'Toggle DescriptionA')
ProbablyEngine.toggle.create('toggleID8', 'Interface\\Icons\\some_icon_nameA', 'Toggle NameA', 'Toggle DescriptionA')
end
ProbablyEngine.rotation.register_custom(specID, "description", {--[[ combat priority ]]}, {--[[ outside combat priority ]]}, onLoad)
You don't create a new function for every toggle, you create one function for whatever you need your rotation to do while loading.