Could you transfer this issue to an appropriate module?

Phenomenon: 
1. Start one of the applications Draw, Impress, Writer and Calc. 
2. View > Toolbars > Drawing, if necessary.
3. Draw a line.
4. Choose Arrow as a type of the end.
5. Increase the line width by clicking on the spin button in the Drawing 
   Object Properties toolbar.
 Results 
  - With Draw and Impress, the width of arrow also increases. 
  - With Writer and Calc, the width of arrow does not increase. 

Comparison: 
1. Start one of the applications Draw, Impress, Writer and Calc. 
2. View > Toolbars > Drawing, if necessary.
3. Draw a line.
4. Choose Arrow for a type of the end.
5, Choose "line..." from the context menu.
6. Increase the line width in the Line properties pane of the Line tab by 
   clicking on the spin button.
7. Confirm the line width of arrow in the Arrow styles pane also increases 
   as that of Line properties is increased. 
 Results 
  - With all applications, the width of the end also increases. 

Additional behavior 
1. Start one of the applications Draw, Impress, Writer and Calc. 
2. View > Toolbars > Drawing, if necessary.
3. Draw a line.
4, Choose "line..." from the context menu.
5. Confirm the default value of width of arrow in the Arrow styles pane. 
  Results
   - Draw:    0.30cm
   - Impress: 0.30cm
   - Calc:    0.20cm
   - Writer:  0.35cm
The default values seems different among applications.

Expectations: 
 It would be better, if an action of changing the line width via the Drawing 
 Object Properties toolbar led change of arrow width accordingly in both 
 Writer and Calc as Draw and Impress do. 

References: 
http://oooug.jp/faq/index.php?faq/4/1179 (Japanese) reported by EighthRest