I just got the NUC8i7HNK. I am getting CORSAIR Vengeance Performance 32GB (2 x 16G) memory (CMSX32GX4M2A3000C16). Can I use the Intel Optane 32GB memory module (MEMPEK1W032GAXT) in one M.2 slot to boost a SAMSUNG 970 EVO 250GB SSD (MZ-V7E250BW) in the other M.2 slot? I am seeing conflicting data that it will not boost a SSD in the other M.2 slot.
No! You use Optane modules to accelerate the read performance of HDDs. You can't accelerate the read performance of a NVMe SSD (it is just as fast as the Optane module already).