Sankey diagram arrow shapes

Dear all,
I have read the 3 Sankey diagram examples.
The first example shows arrow shapes with the default value for angle while the second example shows arrows with180 degree angles which make them look like a flat line.
Does anyone know if it would be possible to mix the two styles inside a single diagram ? I would like some flows to be represented by the regular arrows and some other flows to be represented by the 180 degree angle.

Best regards,
Fabrice