The only parameter we have changed for our comparisons is the new spectrophotometer - the Barbieri Spectro LFP v3. We have not changed anything else (profiling software and settings, RIP, printer, inks, paper etc.). We are and always have been using the Ergosoft PosterPrint RIPs Epson 11880 HTM driver (halftone module) because of ist superior dithering etc. Therefore we are setting the ink limits in the profile. No, we are not using a polarization filter. We have always been converting all RGB images to printer CMYK in Photoshop with the relative rendering intent and black point compensation.
Regards,
Stefan