In order to change the parallelism of the ORB extractor, please modify the code according to the comments in the source files. The default in the code is 4 parallelism.
The <path-to-proj>/HW/rtl/Heapsort/ip folder holds the IP of Heapsort packaged with Vivado 2019.1.
The source files for Heasort IP are in the <path-to-proj>/HW/rtl/Heapsort/src and <path-to-proj>/HW/rtl/Heapsort/hdl folders.