Your fine,no need to bother with flushing it and going back to ATF+4.Chrysler just cutting down on the number of fluids it has to stock at the dealers so they just state ATF+4 for the trans,t-case,and PS system.They even have a TSB that states that but does not effect the WJ's with the hydraulic fans as those require a special PS fluid.
Since your PS system is it's own system you can safely run any ATF,PS fluid,and any engine oil up to 30wt with zero issues.ATF+4 is about equal to 5w-20 engine oil.Same goes for the t-case,you can run any ATF without issues and 5w-20/30 engine oil if you so choose.It's the trans that you must use a authorized ATF+4 trans fluid in.