It's likely that different versions are for different models (performance vs standard), but all fall under v4.1.
That way they can address say a safety related throttle mapping issue on a performance model, while still working on bugs for a 60kw model with supercharging. That way forum members only need to concern them selves with getting 4.1. Once you have it you have it.
Also this way you can have a team dedicated to bug fixes, while another team works on future enhancements. Example 4.1 for performance models gets sent over once the bugs are fixed to the 4.2 team. Once the 60kw with supercharge 4.1 is bug free it gets sent to the 4.2 team