Having reached not only the Nut Coin limit on Nut Cases but even the Spell Trace limit as well, I figured I might as well make a thread about my observations. These conclusions were reached by getting 502 Nut Coins from sources other than Nut Cases, over the course of five days. I've only started farming them in the last three though.
It takes less than 300 Nut Cases to get the daily 30 Nut Coin limit.
From looting, the ratio of Nut Cases to Shining Santa Boxes is 4.4:1
From opening Nut Cases, the ratio of Nut Cases to Spell Traces is 1:1.5
*From opening Shining Santa Boxes, the ratio of Shining Santa Boxes to Nut Coins is 1:0.5
This does not include Nut Coins from Magic Christmas Sock item pots.
These were obtained using a farming method and permanent 2.2x drop, in which..
1 run, including walking to map, NPCing, killing mobs, takes approximately 20 minutes.
During this time, an Elite Monster is spawned about once every 4.5 minutes.
During this time, a little over 1,000 mob ETC drops are collected.
Result is about 110 Nut Cases and 25 Shining Santa Boxes.
2 hours, 24 elite monsters, and over 6000 mob kills later.