Why does Adobe Express Canvas Integration not allow Embedding/RCE use?

The integration to the Canvas LMS for Adobe Express only allows Adobe Express to be used in Assignments. Why does it not also allow professors to access files from the Rich Content Editor? The Adobe Creative Commons link in the menu shows all of the designs a person has made, but you cannot do anything with them except download/upload from Adobe itself. Why can't I select an item from that library or from the "plug" in the rich content editor and add the item to a page? This would be useful to add graphical interest to a class, to add presentations designed in Adobe Express as embedded items on a page (especially nice for asychronous classes). I am not sure why the more complex use of Adobe Express is enabled for Assignments but an entire universe of (ostensibly simpler) uses is completely unavailable. Another strike against the use of Adobe Express for higher education. (The other- no native ability to add hyperlinks.) Weird choices, Adobe.