Hello,

> Now when trying 
> boot scsi-int/sd@3:0,\ofwboot.xcf netbsd.macppc
> I get a 
> "unrecognised Client Program formatstate not valid"

Omit the partition number, OF will pick the first one it understands.
Capitalization shouldn't matter but I'm not sure about buggy and weird
Apple OF 1.0.5 so it may be worth a try. Finally, try with ;1 appended
to each filename: boot scsi-int/sd@3:,\OFWBOOT.XCF;1 NETBSD.MACPPC;1

good luck
Michael