You can still punch in according to the strategy of 3. 13, but you can punch in according to Northrend's new formula after 375. You can rest assured of that. However, if 350-375 uses 70-grade materials, it is better to use new materials after 80, saving money. In other words, you only need to collect 1-350 materials, and then punch holes with 80 new materials.

Also remind you that jewelry depends on prestige. If you want to rush jewelry, you should rush reputation first.