There is a feature in Glyphsapp for ornaments (ornm). But InDesign doesn’t have an OpenType feature called Ornaments. Of course I can access the ornaments from the glyph-menu. But is there another way to access a set of ornaments in InDesign?
There is no interface. The feature is to aid Indesign to keep track of what glyph to show if you selected it from the glyph panel.
Photoshop has Ornaments OT feature. You can code it as ssx on Indesign and ornm fallback for Photoshop.