There is no such possibility now.
But it's a easy to do it by edititng project file.

If you look into project file, the structure of files is simple
Under [Project tree] section is tree of files and folders
level = real tab
first level is name of the project - mandatory
folder begins with "+" or "-" sign (expanded/collapsed)

You can simple open all PPR files (rename extension to TXT) or in PSPad go to
Open - don't dblclick it to prevent open it as project.

Copy content of the [Project tree] section without the first level and copy it
to end of [project tree section].
You can add folder for each project (increase level of one tab)

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<https://forum.pspad.com/read.php?2,74175,74177>
PSPad freeware editor https://www.pspad.com

Odpovedet emailem