Well, this is a bit awkward. Transition (and nose cone) presets that had a <Filled> parameter in the database, even if it was <Filled>false</False>, would always be set to filled, because of loadFromPreset in SymmetricComponent.java:

@Override
protected void loadFromPreset(ComponentPreset preset) {
if (preset.has(ComponentPreset.THICKNESS)) {
	this.thickness = preset.get(ComponentPreset.THICKNESS);
	this.filled = false;
}
if (preset.has(ComponentPreset.FILLED)) {
	this.filled = true;
}

super.loadFromPreset(preset);
}

Which was called in Transition:

@Override
protected void loadFromPreset(ComponentPreset preset) {

  boolean presetFilled = false;
  if (preset.has(ComponentPreset.FILLED)) {
	  presetFilled = preset.get(ComponentPreset.FILLED);
  }

  ...

  super.loadFromPreset(preset);   // This was the issue
  
  fireComponentChangeEvent(ComponentChangeEvent.BOTH_CHANGE);

}

The result: all transition and nose cone presets that had a Filled parameter in the database, which includes not all, but still a fair amount of parts, were incorrectly set to Filled and also had an incorrect mass (if no mass override was set).

The SymmetricComponent should have checked the value of the Filled parameter (which can be false). I have not found any component presets that did not explicitly define a true or false Filled value, so I'm not sure where the original code originates from.

Together with this PR fixes #2614 and fixes #2480.