I use Xournal++ for PDF annotation. Download link.
Go to Edit/Preferences
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- Averaging method
- Arithemtic mean
- Buffer size 10
- Arithemtic mean
- Preprocessor
- Deadzone
- Deadzone radius 1.30
- Deadzone
- Minimum pressure 0.76
- Pressure multiplier 2.01
- Dark theme
- Cursor icon for pen = Big pen icon