I have general-purpose refill inks in my 1100 and not specifically heat transfer inks. I can't get good blues out of it either, it has the same dull blue gamut that the old C88/C88+ had. Profiled, the colors were more "vibrant", but still not what I needed (bright sapphire, light cyan, and teals). I think it's the nature of the beast and nothing to do with the inks. I refuse to try the OEM inks in my 1100 because I'm trying to sell them, but I did try the OEM inks in my C88 way back when and it made zero difference. I think some people simply don't notice or don't have a problem with Epson 4-color pigment low gamut, while other people need better color matching.
I need to send some prints from my 1400 with pigments in it out for color profiling. My R220 with pigments was more than capable of printing the bright blues that the C88 could not deliver, so I'm hoping the 1400 will be able to do it too. Some of my unprofiled tests have output the right color blue from the wrong color swatches so I think it will work.