Yes, Catch.js loads synchronously by default.
No, Catch.js initalizes asynchronously.
Yes, Catch makes use of caching in order to load Catch UI elements as quickly as possible for the highest percentage of consumers as possible. Specifically, Catch caches Catch.js both on the customer’s browser and using a CDN (Content Delivery Network).
catch.js (~72 kB) to display and manage UI widgets,
index.js (~3.1 kB) to manage lazy loading, and