Feature Improvement (Plugin/Slash commands)

There is a huge issue with the implementation of plugins and slash commands -

There is a env variabel for Hooks and other elements to find the plugin root - but there is none for slash commands so if a custom slash command wants to have a companion bash script added (like spec kit does) I have done it for almost all my slash commands some kind of context enabler feature it will never be able to find it in
!'$CLAUDE_PLUGIN_ROOT/scripts/helper.sh'

That is a bit bummer especially when it is integrated in MCP and Hooks - so why isn't it in the slash commands as well?