Suboptimal use of Promise in client.js

[AndriySymon]

What is the current behavior?

If the current behavior is a bug, please provide the exact steps to reproduce.

What is the expected behavior?

Additional context
Add any other context about the problem here.

The methods buildMap(), start(), uploadImage() use new Promise, although Promise.all() returns a Promise anyway.
For example, in start():
return new Promise(async (resolve) => {
const assets = await Promise.all(this.loadAssets());
resolve(assets);
});