To identify the main differences in the treatment of the 'protected' group versus the 'unprotected' group based on the provided process variants data, lets compare several key aspects:

1. **Variety in Process Variants**:
   - Protected Group: A noticeable variety of process variants, including more steps and conditional paths such as "Request Co-Signer On Loan" and repeated steps like "Make Visit to Assess Collateral."
   - Unprotected Group: Fewer process variants with less complexity; there's an option of "skipped_examination" that is not present in the protected group data.

2. **Loan Denial versus Loan Agreement Signatures**:
   - Protected Group: Several process variants end with "Loan Denied," and a few fewer instances of "Sign Loan Agreement."
   - Unprotected Group: A mix of process variants ending in "Loan Denied" and "Sign Loan Agreement," but with a higher frequency of signings compared to the protected group when considering the total frequency.

3. **Frequency of Steps Occurring Before a Denial or Approval**:
   - Protected Group: Steps such as "Request Co-Signer On Loan" and "Make Visit to Assess Collateral" occur with some frequency before loan denials, indicating these steps may be barriers to loan approval.
   - Unprotected Group: Similar steps occur, but also ones like "skipped_examination," which appear to bypass certain checks, potentially leading to faster loan approvals.

4. **Performance (Execution Time)**:
   - Protected Group: The performance times show high variation, with several processes taking longer (represented by higher numbers in performance metrics).
   - Unprotected Group: Generally, performance times are also high but with fewer extremely high outliers, indicating that there are fewer cases of prolonged processes.

5. **Appointment Access and Denials**:
   - Protected Group: Appointment denials are a part of both groups' processes, but we would need to compare the relative frequencies in relation to the overall group sizes to understand if there is a disparity.
   - Unprotected Group: With lower frequencies in denied appointments, it suggests at first glance that this group might face fewer barriers in this step.

To summarise, it appears that the protected group may face a more complex and time-consuming process to obtain a loan, with more steps involved that could possibly act as barriers. This group also has fewer instances of loan agreements being signed, with more frequent denials. The unprotected group seems to have more streamlined processes and a higher success rate in terms of signing loan agreements. The presence of "skipped_examination" is a notable difference suggesting a potentially less stringent evaluation process.

However, more analytics would be needed to confirm these assumptions. The raw frequency numbers should be normalized to account for the total number of applications in each group. Statistical tests for significance might also be required to draw definitive conclusions about unfair treatment or discrimination, as well as considering other external factors such as differences in credit history, loan amount, etc., which are not included in the data provided.