The comments for the progressIni property in ablunit-test-profile.json (from test_projects/proj0/.vscode/ablunit-test-profile-verbose.json) say
////# Notes:
////# * When the value provided resolves to an existing file it will be copied
////# to the "tempDir" before test execution.
////# * If no value is provided or the file does not exist the extension will
////# attempt to create a default progress.ini file in the "tempDir".
////# * A blank value will remove the related args from the command line.
"progressIni": "",
However, specifying a blank value results in a runtime failure
The comments for the progressIni property in ablunit-test-profile.json (from test_projects/proj0/.vscode/ablunit-test-profile-verbose.json) say
However, specifying a blank value results in a runtime failure
There are also errors when a null value is used.