BlueStacks 1 0.9.30.4239 + ROOT KitKat 4.4 is quite an old version; it is still used but only in computers with 1GB RAM and 2GB RAM, if you have a low-end PC. You can use this version of BlueStacks. It is the latest version of BlueStacks 1. In it you will also get to view the key mapping but not the latest key mapping.
BlueStacks 1 VS Latest BlueStacks
The latest version of BlueStacks and old BlueStacks 1 is not comparable because BlueStacks 1 is an old emulator; its Android version is old even though all the features in it are old. The KEY mapping is quite limited, but if we talk about the latest version of BlueStacks, then inside it you get the latest Key mapping. You can run heavy apps. But you need to have a heavy PC to run the BlueStacks latest version, now you have to look according to your requirements to see which one you should use.