QProcess::start introduces a 50ms delay in UI thread

Each call to QProcess::start introduces an approximately 50ms halt of the UI thread. Launching multiple QProcess::start calls in quick succession introduces large delays that pile up and make the UI momentarily unresponsive.

Looking at events with the eventFilter, I see the 50ms delay generally associated with a QProcess_ChildAdded event (or something else preventing event loop processing of the subsequent event). 

If I move the QProcess and their invocation calls to a worker thread, the delay is still present in the UI thread, except now the delay is not associated with the QProcess_ChildAdded event, it is associated with whatever event is coincidentally happening during that time, indicating that the delay is happening somewhere outside of the event loop.

Is a 50-60ms overhead in QProcess calls expected? Is the fact that that overhead isn't hideable in a worker thread also expected? Is there any workaround? In our application, even a single 50ms pre-emption of the UI thread is not acceptable