MindGenius could be leveraged into doing this kind of thing by changing map layout to a vertical layout such as Outline.
The branch connectors and branch shapes could then be changed to better match what you’d expect to see in a process map such as conditions, input/output or process steps and this all easily done using map or branch styles.
A potential issue would be the flow of control arrows, which in a process flow are normally kept angular. In MindGenius, mental connections would need to be used to achieve flow control arrows and these are unfortunately curved only.
If these limitations are too much to work with then we already support exporting to Visio.