The script successfully deleted several hundrends of thousands records. After that I launched another deployment, 30 minutes have passed, but still nothing happens. The number of records in tsysPackageExecution is slowly growing again. Then I executed the script again, so the package I'd launched executed succesfully. So, the procedure is as foloows: 1. launch the required deployment, 2. execute the script.
Thanks for help, hope the next version will come shortly.