e.g. QNAP has rare hardware combo of half-depth 1U low-power Arm NAS /w mainline Linux support, 32GB ECC RAM, dual NVME, 4x hotswap SATA, 2x10G SFP, 2x2.5G copper, hardware support for ZFS encryption,
https://news.ycombinator.com/item?id=40868855.
In theory, one could fit an Arm RK3588 SBC with NVME-to-PCIe-to-HBA or NVME-to-SATA into half-depth JBOD case. That would give up 2x10G SFP, 2xNVME and ECC RAM.