Please expand crafter slightly

Please let crafters have a "lock all slots to current items" toggle icon in the gui (not "lock valid recipe", though it would double as that)  
allowing crafter to only accept items that match the locked items (and locked items would match before open slots)  
basic players should be able to use the crafter without intricate timing or order setups  

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essentially put a ghost item on any slot that had an item when it got locked  
meanwhile any slot that isn't "blocked" in the existing gui, can accept any item since there's no ghost there  
this would massively expand the possibilities as a filter for redstoners, as well

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use case example:  
X O X  
X S X  
X S X  
where x = toggled slot, o = open slot, s = locked to Stick  
you could then feed an iron ingot or a diamond into the crafter and get an iron shovel or a diamond shovel respectively  

clicking the "lock all slots to current items" button a 2nd time would just clear all the ghosts (maybe visually toggling a giant lock as the button, between base gray and red outlined or opened and closed padlock)