Enhance Modifier Key Visibility and Key Display Customization

[Snowyyyyyy1]

I would like to propose several improvements to key display behavior, especially regarding modifier keys and fade-out logic:

1) Persistent Visibility for Modifier Keys

When holding down modifier keys (e.g., Ctrl, Alt, Shift, Cmd), they should remain visible as long as they are pressed, instead of fading out automatically.
This behavior would be similar to Keystroke Pro and would make modifier states much clearer during key combinations.

2) Independent Display Limits for Modifiers and Regular Keys

It would be very useful to configure display counts separately for:

• Modifier keys (always show all currently active modifiers)
• Regular keys (only show the last N keys, e.g., 1–2)

This would allow clearer visual distinction between modifiers and normal key input, improving readability for demos, tutorials, and screen recordings.

3) In-Place Fade-Out Option

Please consider adding an alternative fade-out mode:

• Instead of keys disappearing sequentially like a queue,
• Keys fade out in place, without shifting the layout.

This would create a more stable visual experience and reduce unnecessary motion in the key display.

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These changes would significantly improve clarity, configurability, and professional usability of the key display system, especially for power users and content creators.