Root Filesystem Size Rquirement for NetBSD 10?

Hello,

Does anyone know whether there is a size requirement for the root
filesystem in NetBSD 10.0 on mac68k when using the sysinst installer?

With a 4 GiB Root+Usr filesystem, I've started seeing errors from the
MacOS NetBSD Booter when trying to boot some kernels. A typical failure
looks like this on a Mac IIci:

Logging to bootlog.txt
Booter version   : 2.0.0
Free heap memory : 9367KB (out of 10240KB total requested)
-------------------------------------
Macintosh type (MACHID) : 11
RAM size (physical RAM) : 65MB
System file version     : 7.5.5
Has AppleScript. Has Control Strip. Has Display manager version 2.
-------------------------------------
Booting...
transparent = 1
Boot error: This kernel is not in a format which the booter can execute.

*********** Boot Stopped. ***********
Restoring Monitor settings...

There errors are not consistent. In one case that I didn't capture, the
booter said it could not seek to the beginning of the file.

The booter is configured to boot "netbsd" directly from the root
partition; would it be better to boot kernels from the MacOS HFS
partition instead?

I saw the error once after re-compiling and using FTP to transfer the
GENERICSBC kernel (MD5 checksums matched). I don't think there's a
problem with my crossbuild environment, which is using NetBSD 10.0 on an
i386 IBM ThinkPad T43.

Do I need to ensure that the kernel file in the mac68k root filesystem
is within the first 1 GiB, or 2 GiB? If yes, I'll just repartition and
use a separate /usr, with / taking up the first 1 GiB.

thanks

-Stan