Are SATA port multipliers supported in -CURRENT?

[Steven Schlansker]

Hello everyone,
I am considering buying a SiI 3132 SATA card along with a 5-1 port 
multiplier.  I'm trying to see if FreeBSD supports such a configuration, 
but the only reference found to port multipliers and FreeBSD was some 
poor, lonely man asking about a "porn multiplier" crashing his system on 
startup. :-p
The thread trailed off quickly, without resolution.

So my question is:  Are port multipliers supported in CURRENT?  Are 
there any caveats?  I don't see anything in UPDATING, the handbook, or 
our friend Google.  I want to check that it is supported before I drop 
$80 on it :)  Thanks a bunch!
Steven