A rather fair review and the partitioning step can be confusing to new users. A first time user should read the Guide a few times and maybe refer to it during install. It renders fine on a smartphone.

https://www.netbsd.org/docs/guide/en/

One thing to note, if you create a separate /usr and/or /var partition, y0u really should (must) add this line or similar line to /etc/rc.conf

critical_filesystems_local="/var /usr"

otherwise you will get odd boot errors/warnings, Dir order does not matter.