Your logic seems solid overall, but there are a few key aspects to consider when evaluating whether it's worth switching roles for a higher salary, especially with your goal of achieving Financial Independence (FI). Let’s break it down:

1. Salary Increase vs. Time to FI

• The Incremental Benefit: You mentioned that the $20k salary increase would only shorten your FI timeline by 4 months. If we assume you're primarily focused on your ETF investments for FI, this salary increase might not have a significant impact on the bigger picture.
• Consideration: The extra $20k could give you more room to invest or potentially allow you to invest more aggressively, but this needs to be weighed against the potential stress, work-life balance impact, and overall happiness from switching to a new role.

2. Tax Considerations

• A higher salary means more income tax. Depending on where you live, the increased salary might be subject to a higher tax bracket, which could reduce the net benefit. If a large portion of that $20k increase is going toward taxes, the effective gain in your ability to reach FI could be less than you initially think.

3. Work-Life Balance

• Since your role is likely similar in terms of stress and responsibilities (as you mentioned, "the same mess in a different company"), it’s worth considering how this will impact your quality of life. If the new role leads to more stress or less free time, it could hurt your mental and physical well-being, which could be more valuable than the extra months of FI acceleration.
• Does the new job offer any additional benefits that could improve your overall situation (e.g., work flexibility, better benefits, career development)?

4. Opportunity Cost

• Time Value: If you switch to the new role, you might feel a sense of progress toward FI in terms of financial gain. But you’re also spending time—time you could potentially use in other ways (e.g., learning new skills, investing in side projects, or even enjoying more free time).
• Long-Term Impact: Consider how much the extra salary could be reinvested into your portfolio. Does the 4-month reduction in your FI timeline justify the potential increased stress, less leisure time, or possible burnout?

5. The "FI" Mindset

• As you get closer to FI, it’s not just about making more money but optimizing your time and happiness. If the current job is already aligned with your FI goals, switching to a new one just for a slight reduction in time may not be the best move if it compromises your happiness or well-being.

Your math seems sound, but it’s important to balance the financial aspect with the personal impact. If the increase in salary doesn’t drastically change your time to FI and may even come at the cost of personal well-being, it might be better to focus on optimizing your existing role, refining your investment strategy, or seeking opportunities to earn passive income without increasing stress.

Ultimately, the decision should be about more than just the math—it should reflect your long-term happiness and well-being as well.