Across builds much more on top of Spring Framework than on Spring Boot. Across applications execute as a Spring Boot application and use some features provided by Spring Boot (like embedded webserver, YAML configuration and devtools).
Auto-configuration, however, is not supported, which means simply adding a starter to your project will not be enough. Many available configuration classes from Spring Boot will also not work in an Across application, because they are setup for a single
ApplicationContext, whereas Across uses a different hierarchy. There is often no actual limitation to using the starter libraries, but some effort might be required to get the right configuration. We can offer commercial support for this if required.
An Across application is quite different from a regular Spring Boot application. Please see the question How is Across different from Spring Framework? for more details.
Increasing compatibility with auto-configuration is a major point for future releases of Across.