Hello mrvortep,
i have 2 SSDs. My cheap one for downloading is on slot 1 with the standard heat sink (evo 970/500Gb).
My OS one (evo 960/1Tb) is in slot 2 with the fan setup. Simply because slot 1"in my personal case" is cooler even without a fan due to very good case airflow.
Including direct 40mm air without a heatsink is cooling that one far below optimum temps. Near ambient temps in idle even.
A heatsink is not needed. The fan is so close and for the small distance so strong that i deem a heatsink almost an unnecessary thermal insulator between Controller Chip and fan.
! A prerequisite for this to work is a fan that can keep the SSD from thotteling.
If that is not the case an included heatsink may soak the heat better by extending the throtteling point further.
Rgds Carlyle
ps for new joiners to this topic: my statement concerns the 3D printed fan mount now. That one is very close. The Asus VRM fan bracket, which works well on slot 2, may have more benefits concerning a heatsink.
edit: the 2080ti did cook my ssd, so i did install the 3D Fan mount again. With my 1050ti i could deinstall it.