If I would teach this module again, I would consider moving OOP to week 3. This will leave more opportunity for practising async callbacks and promises in homework and will directly benefit the subsequent Node module. OOP / ES classes is a relatively stand-alone topic and isn't needed until later in the React module.

One thing missing in JS3 is probably error handling and try-catch.

I'm not clear on what we should teach for '(re)writing data structures (in JSON)'.