To Upgrade a crafting slot, click / tap one of your empty crafting slots to get to the item selection menu. Once there, click the "Upgrade Slot X" button to permanently assign one of your crafting slots as an Upgraded slot, which starts at 250 gems and scales up with each slot. The crafting slot will turn purple, and every time you use that item to craft something, all pre-crafting activities will complete automatically.
You will not be able to pool resources for items you cannot already craft. For example, if an item requires a "good" dirk and you can only craft a "normal" dirk, you won’t be able to use the Upgraded slot.
The Upgraded slot pricing is as follows:
1st – 250 Gems
2nd – 500 Gems
3rd – 750 Gems
4th – 1000 Gems
5th – 1500 Gems
6th – 2000 Gems
7 th – 2500 Gems
8th – 3000 Gems
9th – 3500 Gems