I do not have your answer, but a warning: the laptop only supports up to 3200 MHz DDR4, and does not support XMP memory (such as, say, Crucial Ballistix 3200 MHz). BIOS doesn’t have manual OC options (see BIOS guide). My point being, no supported RAM will benefit from a heat sink.
Here’s another good post explaining the XMP issue, for those that are not familiar.
Hope that helps, and shop carefully!
Edit: if you’re looking at a specific kit, feel free to post it! I (we?) would gladly share what we know.