mpt device shuffling

[Edgar Fuß <ef%math.uni-bonn.de@localhost>]

Strictly speaking, this is not a NetBSD kernel issue.
However, I hope that someone more familiar with mpt(4) has come accross that 
MPT "feature" before:

One additional oddity I faced with Thursday's disc failure was that after 
physically replacing the failed disc with a spare, the SAS controller decided 
to assign a new pseudo target id to the new disc, skipping the old disc's 3
and using 8 for the replacement (still at PHY 3). Since the kernel assigns 
sd and, thus, dk numbers in the order of increasing SCSI target ids, this meant 
my RAIDframe components now became dk2, 6, 3, 4, 5 (not 2, 3, 4, 5, 6 as 
before). Not a big deal, but somewhat confusing at midnight.
I assume that's intentional behaviour to the benefit of some commercial 
or GPL-licenced OS software. The renumbering was persistent accoss both a hard 
reset and a soft power cycle (I didn't try a hard power cycle).
Is there a way of reverting to the old sequence or disabling that nonsense 
in the first place?