I currently use a NUC7i7BNH with a "PCIe NVMe - M.2 Internal SSD" without a 2.5" SSD. Should I be removing the 2.5" SSD tray completely to allow for more airflow inside the case, or keeping it in there?
You want to keep it there. The cooling of the M.2 SSD is accomplished through this tray.
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