[JasonACT]

These are the commands used by the usbUpdater.sh and I would be more inclined to try these first before relying on SWSA having all "the real" QNX utilities in the fs-images...

Here, they terminate any running etfs file-system, and restart it with the -e (erase/format) option:

rm -f /fs/etfs
slay -f fs-etfs-swsa_2048
sleep 2
fs-etfs-swsa_2048 -r 16384 -f 32768 -e -m /fs/etfs


This is how it's mounted when booting

fs-etfs-swsa_2048 -r 16384 -f 32768 -m /
sleep 1
waitfor /dev/etfs2 5 && ln -sP / /fs/etfs


I can see a difference in where it's mounted when formatting, compared to when booting - where it appears to create a non-permanent memory link in /fs to the root mount point. Maybe they don't make it root when formatting in case the format fails? I can only speculate.