@copernicus
Do you think you could add an autodetect wizard to try one function from all the keysets every 2/3 seconds until a keypress?

For example, i chose the "poweron" key and the wizard tries it from the all the keysets of all brands.
Then i could decide to try the "volume up", "program up"...and so on.

At the end, it should be possible to save the detected working codes to create a personal keyset. (that could also be exported to share it)

Concerning unsupported devices..
I suppose there could be a keyset that is already working with our unsupported device... but the hard part is to find which one could be... or accept that the working codes are mixed and shared between two different keysets.