I’ve used CoreOS tools in the past to achieve the same goals. It’s really useful once it works! I hope CoreOS lives on after the Red Hat and IBM acquisitions.
Primary obstacles in 2018 are primarily the lackluster support for ro root filesystems. CoreOS/Alpine are fine. Writable memory filesystems are fine.
CoreOS is not even a little bit dead inside Red Hat after the acquisition. If you're not paying attention to the news from Fedora, CoreOS is alive and well, which says a lot about how it will go downstream.
The IBM acquisition is not final yet.
I just really like the CoreOS ecosystem and I hope that it keeps following the direction that they set in the beginning.