I want an icon picker for the toolbar too, but not the standard icons because they make the toolbar look terrible. Instead of using system/app icons, there could be a decent selection of icons in the style of Artstudio's other icons. The developers can easily get a big collection of icons in the right style from stock/graphic design sites and don't even have to create the icons themselves, just put them into a selector for the toolbar. I really like the new customizable toolbar, but the wrong icon design and the text mess up the interface
SF Icons are okay but selecting them by going back and forth between the apps is obviously not ideal...
Edit: I just had an Idea, since you have support for the SF icons, you (art studio) or we (forum members) can make a list for SF icons that fit well to the functions and you (art studio) can make these icons the default name for each function, then the right icon will automatically be selected when someone adds it to the toolbar