OK to use /mnt/userrw for own purposes?

Would it be OK to use /mnt/userrw for our own purposes?
As far as I can tell, it is mounted off mtd15,ubi4_0(swirw) , but is unused by Legato.

If yes, unused. How can I place a ubifs volume in a .CWE file to flash it? (eg. with yoctocwetool.sh / hdrcnv)

Thanks in advance /Flemming

it is for internal usage…