I have been experimenting and i found that two standard or two golden Aggem Thorncurse do not trigger each other, however a standard Aggem Thorncurse can trigger a golden Aggem Thorncurse and vice versa.
which means this works: [standard] [golden] [standard]
but this does not: [golden] [golden]
due to the apparent infinite animation i left the game and re-joined to skip the animation, where it turned out that the trigger eventually stops - i am guessing it hits a hard coded limitation in maximum spells.
it was quite fun, but i guess this is not supposed to behave like this.
If you are interested, my final values have been 21736/66841 for the biggest one