how about this one?
I know wm2 only fits single sided m.2 but they don't list that anywhere.
I searched the Crucial product pages for the P3 and P3 Plus
https://www.crucial.com/ssd/p3/CT4000P3SSD8
https://www.crucial.com/ssd/p3-plus/CT4000P3PSSD8
as well as the Amazon product pages
https://www.amazon.com/dp/B0B25P44CL
https://www.amazon.com/Crucial-Plus-PCIe-NAND-5000MB/dp/B0B25M8FXX
and could find no reference to "HMB" at all on the product page, in the Q&A, and in the user reviews. On Amazon, there were 6 times in the P3 Plus Q&A, when people asked about DRAM, that a Micron rep answered that there is no DRAM but he failed to mention anything about HMB (which would have been a plus). Maybe the P3 and P3 Plus had HMB at one time but the status seems to be secret now.