- created a new custom layout based on the Grid Layout where I can set the horizontal and vertical spacings between grid items and used it throughout the app

appGUI/preferences/tools/ToolsMillPrefGroupUI.py

@@ -2,7 +2,7 @@ from PyQt6 import QtWidgets
 from PyQt6.QtCore import Qt
 
 from appGUI.GUIElements import RadioSet, FCDoubleSpinner, FCComboBox, FCCheckBox, FCSpinner, NumericalEvalTupleEntry, \
-    OptionalInputSection, NumericalEvalEntry, FCLabel, FCComboBox2, FCEntry
+    OptionalInputSection, NumericalEvalEntry, FCLabel, FCComboBox2, FCEntry, FCGridLayout
 from appGUI.preferences.OptionsGroupUI import OptionsGroupUI
 
 import gettext
@@ -28,7 +28,7 @@ class ToolsMillPrefGroupUI(OptionsGroupUI):
         )
         self.layout.addWidget(self.mill_label)
 
-        grid0 = QtWidgets.QGridLayout()
+        grid0 = FCGridLayout(v_spacing=3)
         self.layout.addLayout(grid0)
 
         # Tooldia