Based on the provided process variants, I've generated a list of 20 relevant questions with corresponding confidence scores. The confidence scores are subjective and reflect my assessment of the likelihood that each question is relevant to understanding the process.

1. What is the average time it takes for an employee to submit a declaration? (Confidence: 8/10)
2. Which variant has the highest frequency? (Confidence: 9/10)
3. What is the most common reason for rejection in the approval stages? (Confidence: 7/10)
4. Are there any patterns or trends in the performance metrics across different variants? (Confidence: 8.5/10)
5. How many times does the SUPERVISOR approve a declaration before it reaches final approval? (Confidence: 6.5/10)
6. Can you identify any bottlenecks or delays in the process? (Confidence: 9/10)
7. Are there any correlations between frequency and performance metrics? (Confidence: 8/10)
8. How often does an employee need to resubmit a declaration due to rejection? (Confidence: 6.5/10)
9. Which variant has the lowest performance metric? (Confidence: 7/10)
10. Can you identify any variations in the process that might impact payment handling? (Confidence: 8.5/10)
11. Are there any notable differences between the frequency of submissions and approvals by different roles (EMPLOYEE, SUPERVISOR, ADMINISTRATION)? (Confidence: 9/10)
12. How does the performance metric change as a declaration moves through the approval stages? (Confidence: 8.5/10)
13. Are there any cases where an employee's declaration is approved and then rejected again later in the process? (Confidence: 7.5/10)
14. Can you identify any patterns or correlations between the number of rejections and performance metrics? (Confidence: 8/10)
15. How often does a declaration need to be resubmitted due to missing information or clarifications? (Confidence: 6/10)
16. Are there any notable differences in the frequency of submissions and approvals across different roles (PRE_APPROVER, BUDGET_OWNER)? (Confidence: 8/10)
17. Can you identify any cases where an employee's declaration is rejected without being resubmitted? (Confidence: 7.5/10)
18. How does the process change if a declaration is submitted multiple times due to rejection? (Confidence: 8/10)
19. Are there any correlations between the number of approvals and performance metrics? (Confidence: 8.5/10)
20. Can you identify any potential improvements or optimizations in the process based on these data? (Confidence: 9/10)

Please note that these questions are meant to be a starting point for further analysis and investigation, and may not cover all aspects of the process.