I am currently tracking to FI by 4/1/2026 with a 3.5% SWR. It would be 10/1/2023 @ 4% SWR. But that's not the point. I recently refinanced and went from $1605 P+I to $1305 P+I and boom, my 3.5% FI date came to 11/1/2024. A full 17 months ahead of schedule. That gives me time to save even more or weather out any uncertainty in that time.
TL;DR - Refi'd and saved $300/month on mortgage. Moved up FI date by 17 months.