models/classes/compilation/CompilationService.php
public function useClientContainer()
    {
        if ($this->hasOption(self::OPTION_CLIENT_TESTRUNNER)) {
            return $this->getOption(self::OPTION_CLIENT_TESTRUNNER);
        } else {
            // fallback to taoQtiItem config
            $itemModel = $this->getServiceLocator()->get(ItemModel::SERVICE_ID);
            return $itemModel->getCompilerClass() == QtiJsonItemCompiler::class;
        }
    }
public function useClientContainer()
    {
        if ($this->hasOption(self::OPTION_CLIENT_TESTRUNNER)) {
            return $this->getOption(self::OPTION_CLIENT_TESTRUNNER);
        } else {
            // fallback to taoQtiItem config
            $itemModel = $this->getServiceLocator()->get(ItemModel::SERVICE_ID);
            return $itemModel->getCompilerClass() == QtiJsonItemCompiler::class;
        }
    }
Whenever or not to use client container for test runner
Fallback determined by qtiItem model extension
@return boolean