Okay, glad to hear it then!
Hm, by default, everything should be recycleable, unless it fails one of 2 or 3ish checks for validity; probably the most important check is that the item and the recipe must have the same internal name, otherwise it won't be picked up at all. If the names are different, I have methods for other mods to add in their "custom" reverse recipes, which I have detailed somewhere if you need it.
Apart from that, the recipe must have valid ingredient counts (single ingredient cannot exceed 65536, or some hugely large number, and it cannot be zero), and cannot include probabilities. There's also a list that other modmakers can use to outright exclude certain recipes from being recycled, but I doubt that applies here. But those should be the only conditions.. if it doesn't break one of those rules, then I can only guess what the issue might be, without seeing the code structure (or rather, what the item structure looks like internally)
My first guess might be that the armor is using other armors or unstackable items in its recipe? Like armor with equipment grids can't stack, so if you make a recipe with 2 of those armors, then the result might be unrecyclable. The last I remember though, I made it so that it CAN be recycled, but you only get one back (because of Factorio restrictions, I can't put 2 of an unstackable item into a single output slot, and can't use more than one output slot for the same item type)
