quoted

The kernel starting point would be that we have an AHCI driver. If you
need workarounds for hardware errata then they can go into it and that is
fine. We support NCQ so we can use the queue depths. If there are
extensions then the AHCI driver can be enhanced.

Given the highly parallel nature of these parts, I wouldn't be surprised
if the ahci queue depth of 31 is one of the main bottlenecks.  Can you
think of a way to extend the ahci driver in this manner to accommodate
devices like this one?

The queue depth and tag limits come from the SATA standard and also leak
fairly comprehensively into the AHCI spec so not unless the hardware has
extensions for it and is merely faked SATA (and if you are faking SATA
you have to wonder why if your goal is max performance)