Greetings to all this may concern,
I've been using Here JS SDK for a year, and recently I'm gathering efforts to get my app most performatic and lighweight. My project started with create-react-app v4 (webpack 4), and in order to upgrade to better options, I've migrated to vite and its been working fine. To lookup for bundle sizes, I have a tool showing every dep size, so i can improve loading times.
The JS SDK represents almost 30% percent of the assets, I think this can be optimized to reduce the bundle in client side. The adoption of ESM may be a good choice to get better results.