Hi Tim, unfortunately I can't give you a straight answer. Part of the problem is that when you use CS4, whether or not you experience a problem depends on the combination of OS version, driver version, and printer model. I have not personally tested the print path from CS4, 10.4.11, and 7800, so I cannot say for certain; remember, it may also depend on which Epson driver version you have installed for your 7800.
If you wish to play it safe when printing profile targets, I suggest using the workaround for the time being. It will work under 10.4.x.