As per the FAQ, SonarLint doesn’t support third-party analyzers, and there’s no plans to do so. The reason given is that these analyzers already offer their own integrations.
While that reason is sound, there would still be benefits of supporting them, at least when using Connected Mode. Since Connected Mode is used to reflect a SonarQube Server configuration in your IDE, being able to run the exact same rules in both places would make fixing issues much easier.
Also, there aren’t always integrations from third-parties to every IDE. VSCode, for instance, lacks a FindBugs (or SpotBugs) integration. And even when there is, it would still require that you configure said integration to mirror your SonarQube configuration, not to mention updating it if it ever changes.
In summary, I’m asking to reconsider third-party plugin support in SonarLint to better integrate with SonarQube through Connected Mode.