I've been using the V2 scripts for a while now to get SCSS support without tinkering or ejecting. They just work. When I look at all the dependencies in NPM for create react app I always shudder (I think am allergic to complexity) but it 'just works'. Kudos to the team!
Good work... I'd been rolling my own configuration by hand, I may give another look at create-react-app in the future. Good on them for dropping IE9-11 support by default. Lack of generators+async is a pretty big issue imho as the transforms and fills are pretty significant in terms of size/overhead. For a while I had been doing two build targets, one for modern es2017+ and one for older IE9+ browser. Recently dropping IE altogether.