I got bored and made a rhino mount for a headlamp. It holds on tight so you don't have to use a flashlight or use the headband. It for sure fits the Princeton Tec Remix 300. All it needs is an M5x12 bolt and an M5 nut. Heat the nut with a torch or a soldiering iron to set it in the hole in Locking Clip.

Headlamp- https://www.amazon.com/Princeton-Tec-Headlamp-Lumens-Multicam/dp/B07BQKY5YK/ref=asc_df_B07BQKY5YK/

Bolt example- https://www.amazon.com/PZRT-Button-Socket-Screws-Stainless/dp/B07F72LQX6