I can see doing a 2nd extraction/2nd run on elderberries. Granted, the 2nd run will be lighter than the first, but it should produce a good outcome.PS there are a couple of recipes for a 2nd and a 3rd extraction from the Elderberries!!!
3rd extraction? That one I'll question. I've had 3rd run grape wines that tasted mostly like colored alcohol, with very little grape character. I've not tried it myself.