tough is one of the actual oss gems behind bottle rocket thats reusable in non aws contexts.. bottle rocket probably can be but likely that will always be a second class citizen, and afaics completely undocumented for usage outside of aws atm.
As far as running in non-AWS contexts, we haven't had time to head down that path yet, but as I mentioned in an earlier post, we've tried to build Bottlerocket in a way that it can be extended to work outside of AWS either as VMs or even bare metal. In fact, a few of the engineers on the team have been playing with getting it running on their RaspberryPi's at home :)