Presence of xml config file increases memory consumption by 3

The video is self-explanatory:

xfwm4

Basically I boot into text mode and:

1. remove all xml config files from ~/.config/xfce4/xfconf/xfce-perchannel-xml/, then I start Xfce session. Memory consumption: around 33 MB
2. logout and start Xfce session (keeping all xml config files automatic generated by last session). Memory consumption: around 100 MB
3. again, remove all xml config files from ~/.config/xfce4/xfconf/xfce-perchannel-xml/, then I start Xfce session. Memory consumption: around 33 MB

I can keep doing this over and over, and the result is very consistent.

Xfce 4.20 running on PorteuX 1.9 x64 using X11.