Nice review of the two studies. Research I've seen puts the 4% rule's forward looking success rate at 87%. Most planners recommend targeting 90%.

A better solution is the so-called Guardrails Approach, which is a dynamic one where you adjust your draw say 10% downward if your inflation-adjusted draw will be 20% higher than your target fraction of your portfolio, and conversely increase your draw 10% if otherwise your draw would be 20% below your target percentage.

Recent Morningstar research supports this approach and shows you can start with about 5.3%, leading to a 30-year average draw of 4.8% with a 90% success rate.