How to use FMX Style Manager to create a fade out effect for TMemo

Question

I am trying to add a fade-out effect to a TMemo control.

In the Form Designer it works quite well with a TLayout, TRectangle, and TMaskToAlphaEffect, as show in the screenshot on the left side. However, I would like to use the Style Designer (TStyleBook), as this seems the predestined approach and offers even more possibilities.

I have recreated it in the Style Designer, and in the Form Designer it looks as expected.

At runtime, however, the fade-out effect is not visible for TMemo styled by the TStyleBook. The "manually" styled TMemo is working fine.

As the Windows resources for the TStyleBook generates a ~83kb .fmx file, I had to upload the MCVE, which can be found on DropBox.

To do it on your own, follow these steps:

1. Open new FMX project
2. Add a TMemo to the form
3. Right click the TMemo and select "Edit Custom Stlyes..."
4. Select "background" under Memo1Style1 in the structure panel
5. Add a TRectangle from the component palette by double clicking
6. Select the Rectange1Style and change
7. Align to "Client"
8. Fill -> Kind to "Gradient"
9. Add a TMaskToAlphaEffect as child from the component palette by double clicking (Rectange1Style still selected)
10. Close the Style Designer and confirm applying the changes

If I change the Z-order of the TRectangle in the Style Designer, the effect also disappears in the Form Designer.

Am I missing something, or is it due to an incorrect Z-order at runtime, or is my approach fundamentally wrong?