It certainly can't hurt to take a class in the mechanics of how to program the particular PLC.
However, those classes generally do nothing to teach anyone how to develop a process. That is simply beyond the scope of any typical PLC Training Class.
Typical PLC Training Classes show you the tools that are available, for the particular PLC, and then provide examples of how those tools can be used in a particular, custom-fitted, process.
Those classes are quite a bit like teaching the tail to wag the dog!
Pretty soon, if he continues with his degree program, Ron will agree.
There's a hell of a lot more to developing a process than simply being familiar with the particular functions available from a particular PLC.
In fact, being constrained to only those functions and the related examples that are illustrated in one of those classes is crippling... in terms of real world process development.
Any PLC user can be an Instuctor at a PLC Seminar.
Get Real...
Considering the time constaints... how much can they really teach?