My experience is that changing the size of the line is not a clear-cut solution, either. You would have to make extraordinary (and uneconomical) size changes to switch the flow regime.

This is because changing the line size affects line speed and pressure losses, but it does nothing to change the relative rates of gas to liquid.

The only acts that control the relative rates is pressure and somehow controlling the mass ratio of gas/liquid. Both of these are inter-related, and boil down to equipment design.

And most process engineers will understandably balk at the notion to allow the pipe to control the design of equipment, as they are also required to design their equipment with their own rules of economics in mind.