Refund clay jars when crafting with Linseed Oil
There doesn't really need to be an explanation for this. Clay jars are actually quite expensive to produce in-bulk (requiring 10 clay apice, which is a pretty sizable chunk of mining equivalent roughly to a full size block for one jar from what I can tell), and late game linseed oil is needed in large amounts when reforging steel tools and when fussing around with mechanical blocks.
Industrial flax farming is a fair requirement as its all a part of the tech progression and assumed that by the time you would need it you would have the means to get it. Flax is also renewable, you can farm the same patch of turf indefinitely. When playing on a server where other players claim lots of territory this is important because you might have a very limited area from where you can find resources like clay.
That and getting your jar back is just... realistic. You don't have to break it to get the oil out, and presumably have the means to clean it out and use it again.
I equate it to crafting a cake in minecraft and losing the three buckets holding the milk.