Maybe you misunderstand me.
The Pi Desktop is just is just a hardware case having an mSATA interface (used for recording movies) and a hardware to switch-on/off the Raspberry Pi. It is not a desktop manager.
I want to use this case but always running LE only. But I need a service running to control 2 GPIO pins for ON/OFF feature.
But I understood, there is no easy way to expand the read-only area. So the only option is some area in /storage.
Thanks for your help.