QTR-Quadtone RIP

Have there been any advances in third party inks for Epson printers in the past few years?

The carbon blacks, both matte and “photo”, seem to have settled down at a satisfyingly high level. (I use MIS BK, PK, LK and LLK.)

But the toning/“colour" inks for cooling (or warming, I suppose) print colour seem to be stalled. Have there been any improvements, especially in archival properties?

Since I like to do some colour printing on my 4880, I keep the standard colour cartridges in place, although I often use QTR for B&W printing.

At present, I stick with the overpriced Epson inks for the non-black inks. Is there anything that is equivalent, or better, these days?

Myron