Position of Arrows from a Study in Lower chart

[jrandydavis]

Hello all. I've got a basic question about the (vertical) position of Study arrows/points/etc when used/displayed in a Lower chart.
Background: I've got one chart open with 3 subgraphs: Price, Lower, and Lower (Volume subgraph disabled via Chart Settings). Currently, the studies reside in the first Lower subgraph, which is used to display my MACD data/graph, and one looks something like this:

plot MACD_TOP = If MACD().Value[4] > MACD().Value[0] AND MACD().Value[3] > MACD().Value[0] AND MACD().Value[2] > MACD().Value[1] AND MACD().Value[1] > MACD().Value[0] MACD().Value[1] > 0

then (Low * 0.99) else Double.NaN;

MACD_TOP.SetPaintingStrategy(PaintingStrategy.ARROW_DOWN);

MACD_TOP.SetLineWeight(3);

MACD_TOP.SetDefaultColor(Color.RED);

The red arrows are positioned haphazardly (vertically) about the Lower subgraph.

Things I've tried:
** Changed the " then (xxx) else..." to MACD().Value, 0, 1, 100. These do move the arrows some, but not in the way that makes sense (to me).
** Tried Boolean arrows
** Added Declare Lower; at the beginning of the code. This only seems to add an additional and unwanted 3rd Lower chart.

I'd be happy with a way to display the arrows at the top of the subgraph, or at the bottom. Bonus would be an understanding of how to connect the arrow position to some element of the MACD graph, which I have no trouble doing when it's up in the Main/Price graph of the Chart.

Thank you,
JRD