There are actually hidden chests in every forge...some easier to get to than others. Dawnstar is by far the easiest but the Skyforge chest has so much more items than the others that it's worth the effort. I did the same thing, using it for iron to build my houses, it always has a ton of ebony, and more gold than any other hidden chests...If you use your shout to actually land ON the chest, it is so much easier to get the loot and talk to the blacksmith pretty quickly. I have also found that as soon as select "wait for 24 hours" and then hit the XBox button, the time goes by about 60% faster, so the process can go pretty fast!