CollectRates() Being Called Multiple Times

I’m experiencing an issue where the CollectRates() method in my custom shipping module is being triggered multiple times. Based on slow log analysis, this method is called repeatedly, which is causing performance issues.

Questions:

Can CollectRates() be triggered every time a product is added to the cart?

Can CollectRates() be executed whenever Magento creates / updates the product cache?

I’m not sure what direction to look and I’d appreciate a helpful tip.