The two codes C100C and C100D were for the opened connection to the electric Ohlins forks. I connected resistor bypass and the engine light went away.
The other two exhaust valve codes are BBS codes that cannot be removed even with a healtech eliminator. They don't show any engine light anyway.
Sooo now I can finally say: Rebuild complete!
I will update here if the engine has any issue in less than 600miles. But I can re-confirm that it's possible to turn your 899 into an 1199s.