Those complaining about not being notified that Shimmering Embers could be alchemized are just being ?? nitpicky ??
Experiment!! Don't wait to be spoon-fed by staff, the first thing I did was see if I could use them outside the event when I finished the tasks; The majority of the community are full-grown adults, please don't blame other people for sitting down, twiddling your thumbs and not taking a second to go "hey, maybe I can use these items for something else!"
The number of Embers users gained in comparison to how many were actually consumed by tasks - It was a pretty telltale sign they had some other use?