No issues here!
I have burned many TYG02 (106) with excellent results and no speed drop using various combinations of SolidBurn and WOPC. I have also seen improvements in the write quality of OPTODISC 0R8, both Samsung and DataWrite branded, and the TDKG02 that failed to burn completely with BCDC and BCFC now burn fine.
The only negative I have experienced is slower burn times, by about 30-40 seconds when using SolidBurn.
I haven't tested QScan with BCHC, but I find it next to useless anyway. Some TYG02 I burned at 12X reported way off spec TE and FE but burned amazingly well; ie 2 PIF max, 8 PIE max, 3 PIF average.
BCHC has had mixed results allround, with some reporting no change, others improvements and some, like you, negative effects.
Nothing wrong with CMC BTW, although if you expect TY-like results then you'll always be disappointed!