Should different products have different timer strategies?

As an e-commerce manager, I'm struggling to understand how to optimize countdown timers across my product catalog. Each product seems to have unique customer behaviors and conversion dynamics, and I'm uncertain whether a one-size-fits-all timer approach makes sense. Some high-ticket items might require different urgency strategies compared to impulse purchase products. How can I develop a nuanced, product-specific countdown timer strategy that maximizes conversions without feeling manipulative?