Score for Custom Job Description:
1. Job Title: 10/10, 10/10, 10/10
2. Introduction/Overview: 9/10, 10/10, 10/10
3. Roles & Responsibilities (or Job responsibilities): 9/10, 9/10, 10/10
4. Years of Experience: 10/10, 10/10, 10/10
5. Education Qualification: 10/10, 10/10, 10/10
6. Skills/Knowledge: 8/10, 9/10, 10/10
7. Domain/Industry:  10/10, 10/10, 10/10
8. Key Competencies: 7/10, 7/10, 8/10
9. Employment Type: 0/10, 0/10, 0/10
10. Company Overview: 10/10, 10/10, 10/10
11. Benefits & Opportunities: 0/10, 0/10, 0/10
12. Location & Travel: 10/10, 10/10, 10/10

Explanation of Scores:

1. Job Title:
The custom job description clearly states the job title as "HMI Developer," which is precise and matches the benchmark.

2. Introduction/Overview:
The introduction provides a detailed overview of Royal Enfield's history and current standing. It could be slightly more concise for clarity.

3. Roles & Responsibilities:
The roles and responsibilities are detailed and specific, aligning well with the benchmark. Minor details may be missing, such as direct mention of collaboration with stakeholders to define requirements.

4. Years of Experience:
The custom job description matches the benchmark in specifying a minimum of 4 years of relevant experience.

5. Education Qualification:
The education qualifications are clearly stated and align with the benchmark.

6. Skills/Knowledge:
The skills and knowledge required are well-detailed, though some specific tools and technologies mentioned in the benchmark are not listed, affecting completeness.

7. Domain/Industry:
The domain knowledge is clearly stated, with a detailed company background provided, matching the benchmark.

8. Key Competencies:
Key competencies are listed, but they are not as clearly defined as in the benchmark, which could affect clarity and completeness.

9. Employment Type:
No details are provided regarding employment type, which is a critical omission, resulting in a score of 0.

10. Company Overview:
The company overview is comprehensive, providing a rich background of Royal Enfield, aligning with the benchmark.

11. Benefits & Opportunities:
No details are provided about the benefits and opportunities, which is a significant gap, resulting in a score of 0.

12. Location & Travel:
The job location is clearly stated as Chennai, Tamil Nadu, which is consistent with the benchmark. However, there is no mention of travel requirements, which affects completeness but not clarity or relevancy.

The scores reflect a rigorous assessment of the custom job description against the benchmark, with deductions made for missing information or lack of specificity in certain areas.