OT-ish SATA port replicators vs. SAS "expanders"

[Zaphod Beeblebrox]

First... seriously... whoever was working on this naming convention thought
"expanders" was a good name?

Anyways... I don't talk about big piles of disk in any other forum, so I'm
asking here.

The very first different between SATA port replicators and SAS expanders is
that I can find many working examples of the former, while the latter are
very scarce.  The latter also seem to be expensive, as is anything else
labelled with SAS.

I have, for some time, been running a ZFS array that makes uses of SATA
port replicators.  Because I had some CRC errors, someone suggested I look
at other SATA ports, and I settled on the Supermicro clone of the LSI 2008.

The problem with the LSI 2008 is that it doesn't support SATA port
replicators (while it does support SAS expanders).

What is the real difference?  Is it possible to hack the driver to support
(obviously not booting from) SATA port replicators on the LSI?