Option to use/switch to Icon only instead of text

[msmafra]

I would be good for theming/"ricing" if App Library had an icon only mode also, instead of only text.

[git-f0x]

It does. The App Library button applet only uses text on a horizontal Panel below medium size. It's always an icon on vertical panels or on the Dock.
You can install COSMIC Tweaks to force it to an icon on a smaller horizontal panel, until it's built into Settings.