> Is there anything to prevent a "normal"/"traditional" install?

No. This is still an option and explained in the installation notes.

> (3) Load SunOS miniroot into newly partitioned swap partition

The next release will probably see a NetBSD miniroot for the sparc
using the tools currently deployed by the hp300 and sun3 ports.

> Oh, for a bootable NetBSD/SPARC 1.1 CD-ROM with the NetBSD
> bootblocks and "installboot" in the future ...).

This would be nice. Somebody told me you need to do special things to
make a bootable CD for a sparcstation. I forgot what the quirks are..

-pk