It is still improved. The actually also want to add this kind of check-in (almost done) but it might be blocked by apple/google as the terms of use of the contact tracing API forbids use of additional data.

As far as I know CWA will save it on the device and thus comply with all requirements for contact tracing apps.

The CWA is developed under extreme scrutiny wrt privacy. It's really good at what it does, so good that even the CCC gave it it's blessing (despite being made by companies that would traditionally be considered evil empire in CCC, which really puts CCC in a very favorable light for objectivity). But that strength makes it the absolute opposite of move fast and break things.

PS: and I believe that there is hardly a scenario where moving fast even if breaking things is more called for than pandemic response, particularly regarding privacy where most problems are of the kind "if we did that for decades, eventually abusive patterns would develop" - e.g. mass mail voting is fine done a few times, but if it was routine you'd eventually have most ballot forms filled under some form of supervision. On openly privacy-invading tracing method that is so bad that it's clear that it won't survive until after the worst of the pandemic is over might end up being less invasive long term than something that is "so safe that it can become a fixture" (it isn't).

But leaving the fast-moving to those least concerned with privacy is still a recipe for disaster.

Nothing really.

Luca app just had more hype/better marketing.