To overwrite the default set of parameter, edit the multi_params.json file, and add a dedicated named test case or edit one of the existing ones, e.g.:
"test_my_design":{ "DATA_TYPE": "cint32", "COEFF_TYPE": "int32", (...) }
To run a test case, specify the test case name passed to the PARAMS argument, e.g.:
make cleanall run PLATFORM=vck190 PARAMS=test_my_design
For list of all the configurable parameters, see the Library Element Configuration Parameters.