New Parts Have Default Page Margin of 15mm Instead of Inheriting from Score
1) Open "TEST FILE.mscz"
2) Observe that the score has margins of 10mm
3) Go to File -> Parts, then click "All Parts", then "OK" to create a new part for every instrument.
4) Observe that for the individual parts, they have margins of 15mm instead of 10mm from the score.