I doubt you'll see this and I'll have to find a different way to track you down, but with the release of the TF2 SDK, I'm working with a small team of developers and artists to create a standalone 4v4 PASS Time mod that will be published on Steam. One of the custom maps in the current competitive rotation for 4v4 PASS Time, Torii, uses your fireflies particle. I was hoping I could get your written permission allowing us to publish this map with the mod on Steam.
Per the licensing agreement for the SDK, the mod must be made entirely free for all users with no monetization, so this project won't be making money off of your assets. We still understand that crossing the line of "published officially on steam" whether that be on the Workshop or in a standalone mod, regardless of potential profit, is still a big deal for many asset artists, so we don't want to use or publish any assets we don't have the right to publish.