This is my attempt (GitHub) at an automatic fear tracker that listens for duality rolls from Demiplane-linked character sheets and bumps up a game fear counter everytime someone rolls with fear. It sends notices to all players showing the new fear value.

Players can turn notifications on or off as they wish, or simply run !fear to see the current value. As the GM, you can reset and set the fear at any time.

Here's an example, the first roll did not generate fear, but the second did (fear was at 4):

Notices include (which you can tweak in the script if you wish):

• 0 Fear: Have no fear. There is none to be had.
• 1 Fear: There is a single  fear (1).
  
• 2-3 Fear: There is some  fear (#).
  
• 4-7 Fear: There is much  fear (#).
  
• 8+ Fear: There is intense  fear (#).
  

v1.0.1 Updates

• Notices now use a skull emoji before the word "Fear".
• New "spend" command for GMs to do a simple fear spend. !fear spend will deduct 1 fear from the counter then notify players. !fear spend 5 will deduct 5 fear (to a minimum of 0) and notify players.

Nice idea. I have been thinking about fear counters too, but have no preference yet. Just make a few macro buttons and as a GM you can spend fear with the click of a button.

In a video the turn order is used to track fear https://m.youtube.com/watch?v=KXo8YWlia4E. If you would integrate with the turnorder that might make the fear counter display more prominent on the screen.

Or you could use a token with a changing image. A token can be moved anywhere you like on the map. 

Or a row/columns of tokens as a kind of stack that are moved between gmlayer and token layer.

So many possibilities, but i like your solution a lot.