Though the compose mode allows you to combine segments, each segment is still treated individually by operators further down the line. This means that if you connect a compose operator to a transform operator and turn on padding it will overwrite any existing padding values those individual segments were already using.
Instead I've rejigged your style a little to include the glass segment as a part of the Horizontal Frames compose node, dividing the padding values into thirds instead of half to avoid zero sized segments. I've attached the style.
If anything is unclear, please don't hesitate to let me know.