Based on your search for a free automated grading and feedback platform, I recommend Gradescope. This platform offers a variety of features that align with your needs:

1. AI-Assisted Grading: This feature can help you grade written exams and homework efficiently, saving you valuable time.
2. Dynamic Point Adjustment Rubric: This allows you to adjust grading criteria even while grading, providing flexibility in your assessment process.
3. Consistent Feedback: This feature ensures uniform grading across multiple submissions, promoting fairness and consistency.
4. Integration with Learning Systems: If you're using Canvas or Brightspace, Gradescope can easily sync with these systems, simplifying your workflow.

Moreover, Gradescope offers a free basic plan, making it a cost-effective solution for your needs.

If you're also interested in providing personalized feedback, Eduaide could be a valuable addition. Its Feedback Bot can provide instant, actionable feedback on student work, offering valuable insights for improvement. However, it's worth noting that Eduaide doesn't specifically mention automated grading in its features.