Please try perform a simple test. Make scan negative in the CQ as you do it so far. Then do the scan without IT8 and save the RAW 8bit. Then load the RAW file 8bit to PS and convert to 16bit and start ColorPerfect. At the magnification of 100% Compare two scans, you'll see that the scan converted Raw 8bit to 16bit is sharper and the colors are much better.
In fact, the same thing can be done in CT scanning negatives as slides, but a certain advantage over CQ is that it can change the value of Gamma, which has a large impact when converting negatives. Quality scans with CT is exactly the same as with CQ in Raw mode 8bit and can not in any other way, achieve better quality scans. Every other way save files in the CQ will only worsening the quality of scans. The only downside in the CT Scan or CQ Raw 8 bit can be visibility effect "wow & flutter", which is masked by a blur when writing files to TIFF, resulting in a fuzzy, ugly scans.