Let me know what do you think about QtPfsGUI operators.

This is one of the three original bracketed shots:

 

"Sunset (RawStudio output)" by Roberto Ballerini // HAL9000 [?]

and these are four different tonemappings obtained from an HDR composition of the bracketed shots:

NOTE: there are shadows due to movements between the bracketed shots: I haven't used a tripod and I slightly moved.