I confirm I see the same behavior reported above -- setting is written to Notebooks list file but not acted on when next opening the Open dialog. I probably won't be able to fix this for 0.50 but maybe for the next version after that.
WORKAROUND: Create shortcuts pointing to each [Notebook Root Folder]/notebook.zim and launch Zim from those shortcuts.
I confirm I see the same behavior reported above -- setting is written to Notebooks list file but not acted on when next opening the Open dialog. I probably won't be able to fix this for 0.50 but maybe for the next version after that.
WORKAROUND: Create shortcuts pointing to each [Notebook Root Folder] /notebook. zim and launch Zim from those shortcuts.