network が見えなかった件は、 次のように、 -nic user だけにしたら、解決した
The issue network is not connected, has been resolved by simply saying -nic user

  qemu-system-x86_64 \
        -smp 4 \
        -m 8G \
        -accel nvmm \
        -drive driver=qcow2,file=/export/Win11.qcow2,if=virtio \
        -nic user  \
        -rtc base=localtime,clock=host \
        -device intel-hda \
        -drive file=/home/makoto/Downloads/Win10_22H2_English_x64v1.iso,index=1,media=cdrom \
        -drive file=/home/makoto/Downloads/virtio-win-0.1.248.iso,index=2,media=cdrom

(the name says win11, but actually using windows 10 for now)