Inverex seem to have a special arrangement with Voltronic and get their own software with typically 200 W of extra power rating. Inverex specific firmware updates are way less common than "all other brand" firmware.

But if you're prepared to lose the extra 200 W of power rating, you could probably run standard Voltronic King 1 firmware. Alas, the only one I have in version 51.97, which is now 2.5 years old. You quite possibly have more recent firmware than that already.

I imagine that display firmware would be the same Inverex to others, even though they seem to get a custom display as well (with slightly different icons, and the word Inverex appears on it, from memory). If that's the case, you could use the latest Axpert King display firmware, which I believe is version 02.83:

 

Remote Panel_Reflash_MCU(02.83)_GK_MKX Panel.rar