Waveform chart legend flips orientation when programmatically changing # of entries (bug?)

[BertMcMahan]

If you have a Waveform chart with a horizontal legend with, say, 3 entries like this:

And then you decrease the number of legend entries programmatically to 1, then increment back up to 3, you get this:

This isn't great behavior for graphs with dynamically adjustable plots that the user modifies. I can't find a property node that changes the orientation from horizontal to vertical, so once it sticks vertical I can't go back.

Are there any workarounds for this, other than decoupling the legend from the graph itself?

I'd REALLY prefer to keep my legends horizontal. They take up way less space that way.

See attached VI for demo.