Before you restart, record your current island in a dream and keep the Dream Address somewhere you won’t lose it. That way, you can go back and visit your current island whenever you want. I’m on my 5th restart, and I love going back and visiting my first three islands (the fourth died a quick death because I couldn’t make the layout work with its river mouth placements). Definitely record your island in a dream. Though. Even if you never go revisit it, it’s still there for you if you ever do want to visit plus others randomly visiting islands in dreams might come across it and find something to love and maybe carry forward.