No, this class is not public API, and has regularly changed in breaking ways (and is about to do so again). I'm planning to move it out of tools.deps entirely and into the installer project as it's a facet of the CLI, not part of tools.deps.
Really, you should be going through clojure.tools.deps/create-basis for most functionality. I'm aware that there are some gaps between what's in make-classpath2/run-core and create-basis and I will shortly close that distance by enhancing some of the data returned in create-basis (in particular adding the basis config and merged argmap to provide access to jvm / main / exec info).
After that, the major differences between these will be: 1) supporting deprecated CLI stuff (some of which is going away now, some later) and 2) -T support, which really should be more directly supported in the deps api, but that's going to wait for a bit longer. Ultimately, make-classpath2 will use create-basis - that's where this is going.