Quick modification of squashfs

[dani1993l]

Hi all, I am new to the squashfs world and was wondering if there was a way to quickly add a file to a non-root directory of a given squashfs image, without mounting and recompressing the image. I found such a discussion on stakcexchange, though I hoped I could get a more technical answer regarding the possibility of such an implementation - Is it possible? How would one approach such a task? Is there a reason why this has not yet been implemented that I am missing?

Any light shed on this issue would be very appreciated, as I am considering attempting to implement this myself. Thanks and apologies if this is not the place for such an inquiry