A couple of things:
-
Mind Sear may appear to get clipped - when in fact it doesn’t - due to the amount of Insanity you have at any given time.
Example: if Insanity is 100, Mind Sear will be channeled for 2.4 seconds (0.6s * 100/25); whereas, if Insanity is 25, it will be channeled for 0.6 seconds (0.6s * 25/25).

-
The
nochanneling:Mind Searcondition in SPRIEST_DMG_MAIN prevents Mind Sear from being clipped while using the SHIFT or CTRL Key Modifiers:
Having said that, when switching to your Single Target rotation (using no key modifiers) Mind Sear can be clipped.
