Did you know buying certain items in Legion Remix will unlock 
Bronze Cache on the vendor that you can buy with surplus boss currencies? Here’s how it works.
List of Items That Unlock Bronze Caches
The following items require a boss currency and Bronze to be purchased.
The First Satyr’s Spaulders;
Scythe of the Unmaker (coming in a later phase);
Taeshalach (coming in a later phase);
Hammer of Vigilance.
It appears you need to buy them in Legion Remix even when you own them on live servers. After buying each, 
Minor Bronze Caches will appear on the Pythagorus in place of the items.
What’s the Benefit?
If you have say 50 
Horns of the First Satyr in your inventory, you can simply convert them to Bronze, which can be useful. With the raids resetting daily, chances are you will accumulate a lot of boss items really quick and this gives you a good method to convert them to Bronze for rewards.
Thanks to ReaperNevermore for this useful tip!