MSI z370 pro carbon ac m2 slots

[20willshampu99]

I’m wondering which m2 slot I should use for my msi z370 pro carbon ac. There are 2 slots and I’ve seen posts and threads stating that the one with the heat shield actually increases thermals. So I’m wondering if I should use the other m2 slot. Will there be any differences in speed? If it’s true that the m2 shield is actually hotter? Thanks in advance

 

[Supahos]

They appear to both be nvme speed rated though I can't fully confirm this. It shouldn't matter