There is another related ticket below, however, the response from v-deddai1-msft did not answer the question fully. i.e. how can you bypass the dataflow incremental refresh policy using the "processType" URI parameter. The response from v-deddai1-msft was to manually turn off incremental refresh in the GUI which is time consuming. A programmatic approach should be supported.
What I would like to see is the URI parameter "processType" = "processFull" to work. I would expect a similar behaviour to the way that the Dataset Refresh "type" = "full" and "applyRefreshPolicy" = "false" works to bypass the incremental refresh for a dataset (although this is specified in the body, not as a URI parameter)