Exception.getStackTraceString を使用している場合、非同期コンテキストでエラーメッセージが表示されない

global class Thrower implements Queueable {
    
    String namespacePrefix;
    String className;
    
    global Thrower(String namespacePrefix, String className) {
        this.namespacePrefix = namespacePrefix;
        this.className = className;
    }
    
    global void execute(QueueableContext context) {
        try {
            Type reflector = Type.forName(this.namespacePrefix, this.className);
            Object impl = reflector.newInstance();
        } catch (Exception e) {
            throw new StringException(e.getStackTraceString());
        }
    }
    
}

@IsTest class ThrowerTest {
    
    public class Impl {
        public Impl() {
            throw new StringException('got here');
        }
    }
    
    static testmethod void testGood() {
        
        
        String namespacePrefix = '';
        String className = Impl.class.getName();
        
        try {
           
            Test.startTest();
            Queueable job = new Thrower(namespacePrefix, className);
            System.enqueueJob(job);
            Test.stopTest();
        } catch (Exception e) {
           
            System.assertNotEquals('()', e.getMessage(), 'wrong message');
        }
    }
    
}

global class ThrowerService { 
global ThrowerService() { 
throw new StringException('got here'); 
} 
}