Thanks for the careful and detailed comments/suggestions! Let me be a bit more precise in describing the condition of my 4900 pre and post piezoflush (yes, I have a full set of cartridges for piezoflush use only!...thanks for that advice also).
Before piezoflush/ init-fill, I tried all means that Epson had available and after numerous "power" cleans nothing improved the horrible condition as seen by the printed pattern. After the init-fill piezoflush...I waited 48 hrs and behold the printed patterns were greatly improved. With all piezoflush cartridges still in the printer, I tried some paired power cleans for the green/orange pair and saw some improvement but eventually those efforts became fruitless so I let the machine rest another day and did another init fill procedure, waited 48 hrs and now the print pattern was virtually perfect! By this time some colors were showing piezoflush pink (namely C, VM, LK, LLK, Y) while others were pretty much their original hue (OR, GR. LC) and one, VLM, was indeterminate (VLM or piezopink?). Putting my epson cartridges back in shows the same printed pattern, i.e, mostly piezoflush pink. What is the most efficacious way to get all the channels printing their intended colors...Another init fill? Epson power clean all colors? or select pairs? Recall my intended strategy is to start using Conecolors (each with their refillable cartridges) into my printer as I use up my current supply of Epson inks. Thanks again for your comments and suggestions.