It is difficult unless you are very experienced with applying TIM and it is conductive so if ya spill on contacts .... you now have a short.
While I would recommend using it on a delidded CPU, it's advantage is somewhat negate by the problems with the IHS.
Prime95 is NOT recommended for Haswell CPUs as it presents a circumstance that your CPU will never see outside of a synthetic benchmark. Try running RoG Real Bench .... like P95, the Open CL test within the suite of programs that are run will use AVX instructions . This will allow you to see just what voltage spikes you will get under adaptive.
You should be able to get 4.4 GHz (maybe 4.5 with a good bit of luck in the CPU lottery) out of an H100i or any of the big 3 air coolers (Phanteks PH-TC14-PE, Thermalright Silver Arrow or Noctua DH14) on most CPUs