Howdy, The blue elderberry here in the bay area can grow to tremendous size. (One bunch of elders I frequent is sprouts from a cut down trunk ~ 18" across.) I've only cut small branches, so far. The smaller wood is pithy and weak, but I'm thinking wood from a larger trunk may be denser. I believe it is DRUID that has posted multiple bows of European elder. Cutting a larger tree and giving it a try is on my list of things to do.
In the mean time I just collected and processed another 6# of berries yesterday. They store well in a freezer and I've now got almost enough for another batch of wine. I just bottled last year's batch in July. I still have a liter of elderflower syrup from picking earlier this year. Ron