Pope Martin did not instruct Uthman nor any other Quraysh concerning what they should believe concerning Ieso as Messiah because Muawiya does not have any such ideas later. But it may be that there was some kind of communique between Martin and the Alids concerning whatever they had that became Quranic materials. Otherwise, where did the Byzantines get this idea from?
The available evidence does not fit the SIN that Uthman played any significant role in standardising the Quraysh Quran. In contradiction to the Quran, the Emir before Uthman did not know Ieso as Messiah and Muawiya after Uthman did not know Ieso as Messiah. If Uthman believed in the Gospel's miraculously born Messiah Ieso of the Quran, then his belief must have been only a generally unknown personal one which appears did not make any impact on the Umayyads until about 30 years later.
However, the charges brought against Martin show that Christian-like Quranic materials in use among the Muslims were obviously known to the Byzantines at this time but if tolerated were clearly not an Umayyad approved belief (let alone promoted) until about 30 years later during the reign of Abdul Malik.
