How to optimize app to make it lighter and perform better?

I have noticed the newest runtime version created an APK much larger than the one I built with runtime version 3. I was wondering if this has to do with not updating some of the deprecated components. I had done so many customizations I did not want to lose them. Also, this got me thinking about what I have been reading about composite components. I was wondering if it is a better optimization tactic to use composite components and whether the app would perform better? What do you all think? Do composite components create a more optimized component the way web components do in html and JavaScript?

I would stay away from newer builds unless they resolve an issue you are having. Just my personal preference.