How do you think about rebalancing during prolonged equity bull markets.?

In long-term portfolios, rebalancing is often presented as a simple rule, but extended equity bull markets make the tradeoffs less clear. Allowing allocations to drift can improve returns but increases concentration risk, while frequent rebalancing may reduce momentum and create tax or transaction friction. I’m curious how others approach this balance in practice. Do you follow strict calendar-based rules, percentage thresholds, or allow significant drift before acting ? How do you weigh risk control against return drag during long bull cycles.?