Customize KDE Plasma desktop for Live CD

I’m trying to create a Live CD with a customized KDE Plasma desktop (different widgets, panels, etc.). But whenever I try to overlay any file from ~/.kde4/share/config after the testdrive, I get an error on the next build-and-boot: “Call to lnusertemp failed (temporary directories full?). Check your installation.”

Separately, I also tried copying files to /etc/kde4/share and overlaying those instead, but that doesn’t seem to affect the user’s desktop on the next build-and-boot.

I took a look at the SUSE Studio KDE Help page, but it looks like it was written for KDE 3. Has Studio been around that long?

Any help greatly appreciated.