I suppose if you have really good monitoring in place, you could use this approach everywhere. However, what I've found over the years is that some databases need a limit because they're likely to get spurious or weird growth. Lots of other databases grow very slowly over time, so taking away the ability for it to happen automatically is just putting work on you to no purpose. So, a mix is what I've done. Some fixed, with monitoring, and I manually intervene occasionally, the rest all automatic.
The only thing I will say is, get rid of that % growth ASAP. Much better to grow by fixed amounts (said amount determined through experimentation & monitoring) than a fixed percentage which gets scarier & scarier over time.