I have two suggestions for the disklabel part of install.

First, there should be another partition type available at install
time besides dos & netbsd.  "Reserved" would be helpful.  Something to
flag that a partition is, or will be in use, but not by dos or netbsd,
(or at least, doesn't have either of those types).

Second, in my clumsy attempts to accomplish this, I've flagged my c
partition, (i386), as "MSDOS".  My disk is currently unusable.  Netbsd
isn't running and I can't install it.  I can't reset the type of
partition c from the install and with it set to MSDOS, install refuses
to proceed.

So my second suggestion is that there should be a way to reset, clear,
or overwrite an existing bsd disklabel from install.

--rich