We are talking here only about indexed cookbooks. I have some 450 cookbooks, only 188 of them are indexed that makes some 42%. And I'm not counting the titles in foreign languages: italian, french ... So if I'm looking for a recipe with some ingredients I go first to EYB to see the list and decide what to do. Then I go the recipe in the cookbook, or luckily on the web, and see the quantities making a shopping list.
One should keep an eye on perishable food as they are perishable per se so discard them when needed.
Store-cupboard ingredients you should have all time at home and keep replenishing. By the way there is a good UK title called "Kitchen Shelf" which is around some 20-25 core ingredients mixed with some cupboard spices and herbs and a few other ingredients per recipe. Something for young couples. On the other hand Kenji Lopez-Alt stores more than 200 ingredients.
It seems the problem is more in the filtering process which should be more transparent with examples.
I would suggest to give discounts on membership when indexing so one learns the list through doing a useful job, otherwise I would not change a thing.
But let me come back to the beginning of my story. What to do my 58% of unindexed books. Long before I encountered EYB I made in MS Access a list of cookbooks of my own in order to avoid duplicating. Then I added a list of recipes with page numbers and some category fields. Recipe titles in english are quite easy to search with boolean ...
And only if we could post in our private recipe area scans from cookbook recipes. That would be the top is that a real copyright problem?
How to do a reduction is a theme for another post.