The serial monitor tab size is fixed at 8.
"preferences.txt" already works well changing tab size of the editor by changing "editor.tabs.size= "
The ability to change serial monitor tab size by adding "serial.tabs.size= " to preferences.txt sure would be a welcome feature, especially when displaying varying numbers and/or text.
As it stands:
As it could be with "serial.tabs.size=24"
Of course, a Left/Right align feature would also be handy.