Define "hide"? I just tested using a "simple" bobs-angels pack with FNEI, and it seems that the reverse recipes don't show up in either of the tabs (which similarly means they didn't appear when searching). Though I'll admit I haven't used FNEI extensively, so I might be missing something about how it's supposed to be used.
The recipes are all hidden by Factorio standards (meaning, they don't appear in any crafting menu), and I can see a few options in FNEI that enables/disables the appearance of hidden recipes.
You could try disabling that setting, though I imagine it might hide important recipes from other mods as well. I'm pretty sure vanilla doesn't explicitly hide any recipe, since even the furnace recipes appear in the player menu; but other mods might have some hidden their furnace recipes to reduce the size of the crafting menu.
EDIT: Alright, just looked through the settings a bit more, and you can enable/disable specific crafting categories. There are 4 categories defined in my mod, all beginning with "recycle", and during my test pack, they were listed directly below the "smelting" category, nearer to the top of the list.
This disables them from appearing when you open the "Craft" menu in FNEI. That should solve the issue, yes? It reduced my listings of Steel from 242 to just 4, and definitely removed all the recycling recipes from the listings.
