[Fizzlemizz]

Probably adding to MouseLookLock would be easiest.

With absolute minimum testing and no options try changing MouseLook.lua.

After the line:

MouseLookFrame:RegisterEvent("PLAYER_REGEN_ENABLED")

add:

MouseLookFrame:RegisterEvent("CURRENT_SPELL_CAST_CHANGED")

At the very bottom just before the last end statement insert:

	if event == "CURRENT_SPELL_CAST_CHANGED" then
		if MouseLookOn then
			if SpellIsTargeting() then
				MouselookStop()
			else
				MouselookStart()
			end
		end
	end

At around line 254 after the line:

if MouseLook_TempLockout then

and before the line:

MouselookStart()

insert:

	if SpellIsTargeting() then return end

These changes (if they work) would need to be done each time the MouseLookLock addon is updated.