I found info about the A2U8X25S3DPDK in an older version of the config guide at http://static6.arrow.com/aropdfconversion/5f4a362a92dca145c8107a663bfd11ad0e0f3995/2s2600wf_figguide_rev1_1.pdf (it's on page 68)
It looks like it's SAS-only (no NVMe):
Newegg: SAMSUNG 970 EVO PLUS 2TB Internal Solid State Drive (SSD) MZ-V7S2T0B/AM - Newegg.com
B&H: Samsung 2TB 970 EVO Plus NVMe M.2 Internal SSD
Yes it's overpriced compared to any number of other options, but this is the lowest it's ever been...
My guess is that this sub-forum is public (at least partly) because of SEO. STH comes up organically in my searches pretty often (it's how I found it in the first place!), and a good chunk of the useful information is hidden away in multi-year deal threads; they'd be a lot harder to find if they...