Do the QuantiTect SYBR Green Kits contain a stabilization reagent that inhibits the sensitivity of real-time PCR?

No. In fact, QuantiTect SYBR Green PCR Kits contain a stabilization reagent that increases the sensitivity of real-time PCR. The QuantiTect SYBR Green Kits also contain a carefully controlled concentration of SYBR Green that is sufficient to detect PCR fragments while having no inhibitory effect on the enzymatic reaction.