Xnview and conversion xcf Gimp files to jpg format

[gordianknot]

I recently start to use Xnview and find it very useful to view and do all the basic operations with my pictures
I usually edit my pictures with Gimp and I'm glad that Xnview allows me to convert (massive convert) my xcf files produced with Gimp to jpg file format.
I can not understand why Xnview doesn't preserve the white balance even though I have selected the "use camera white balance" flag
This only happens with xcf files, I have to select other options or it is a software bug ?
Thanks in advance to all

[xnview]

this flag is not supported

[gordianknot]

this flag is not supported

The "use camera white balance" flag is not supported only for conversion from xcf files?