@ssh4 (Vlad) posted a new topic, subject "Apple way? (New UX issue)". It read:

   I know Apple is our idol. And looks like idol for SketchFab team too.  
    But sometime i have thoughts that even in Apple working idiots that not made simple tests. Like stupid UX bug in keyboard in vertical/horisontal layout…
    
    But SketchFab, i'm not sure you should follow bad Apple manners. And think much more, at least you do not have huge operation system with all possible languages…
    
    Who proposed idea change shortcut “3” used years in SketchFab for user Matcaps to “6”. For new switching texture layers???
    
    WHY JUST NOT ADD NEW SHORTCUT FOR A NEW FEATURE??? But remain old UX as is… So old user will not affected…
    
    It take 15 minutes to find that there is not a bug that my models open with default matcap and without normals when i pressed 3. But that you moved user Matcap shortcut to 6…
    
    Is it possible switch this back?  
    3 for user Matcap, 4 or 6 for new layer switch?
    
    PLEASE?

To which @stephomi (Stephomi) replied

    The old interface that enables you to switch to shadeless or “user” matcap will be removed soon.  
    So : no more user matcap and shadeless mode.  
    The shorcuts 6 will be removed as well.
    
    Shortcut 2 is cycling through material channels, the first one being diffuse, it's similar to shadeless.  
    Shortcut 3 is cycling through geometry mode, the first one being the “non-user” matcap view.  
    Maybe in the future, we'll change the matcap used in the model inspector.
    
    The main idea is that the inspector is replacing everything.

To which @ssh4 (Vlad) replied

    Marmoset have good example of how it can be done. In precedence for model quality estimation  
    First object details (sketchfab neares was matcap with normal map). Next - albedo/diffuse, glossiness, etc.  
    Low poly matcap without normals is lest useful information about model.  
    Optimized low poly mesh can looks weird but this weirdness can have reason for polygon budget. But without tangent space it tell nothing.  
    Matcap with normal map and wireframe give good information about mesh quality and optimization.  
    In that case 1/2/3 can remain as old UX but still work as your new inspector.


{'source': 'discourse', 'url': 'https://forum.sketchfab.com/t/apple-way-new-ux-issue/17284', 'title': 'Apple way? (New UX issue)', 'views': 628, 'has_accepted_answer': True, 'word_count': 351, 'like_count': 0, 'reply_count': 1, 'participant_count': 2, 'posts': 3, 'tags': '', 'author': '@ssh4 (Vlad)', 'participants': '@ssh4 (Vlad), @stephomi (Stephomi)', 'image_url': [None], 'created_at': '2017-10-27T10:28:48.755Z', 'last_posted_at': '2017-10-27T15:26:01.223Z'}