Been exploring mostly all content and shops, including fishing. 

Counting in the rewards from the latest event's 50-score tier that seems to have been given out ahead of time because it's so bugged, I currently have 11 Twilight Treads as a F2P.

I know 2 extra come from the paid portion of the Bard's Tome battle pass, for a total of 13.

Am I missing any? 

Please reply with how many you currently have and how many are remaining from other sources you've seen and where you find them.