Novice bowyer, so take what I say with a grain of salt. I've made two semi-successful bows from the blue elder in my front yard. The wood seems to have a very snappy return, and lots of tension strength. Compression seems weaker, which fits into it's heartless growth pattern. Design wise, I learned through failure and chrysals to watch out for stress concentrations, which caught me when trying to decide what to do with and around the pith channel. The wood is stringy, lightweight and easily worked with a scraper. The grain is quite straight and non-interlocking. It's nothing like serviceberry.
Blue elders seem to grow taller and larger than red (which is what I'd guess you've got in Haida Gwaii) but I've found some red stems that I'd be willing to try. I think I found some bows posted that were made from Alaskan elder, which should be comparable. There have been a few posted of black elder, and some very elegant hollow-limb designs. Someone recently posted one, and Simson has a few posted in his portfolio.
Bear in mind red elder secretes glycosides in all tissues, so wash your hands well after working with it. It dries fast and works quickly--I say give it a try.
Been shooting some of your shafts I got from Blayne. Super happy with them.