Though it was reported that Ibn Mas’oud may Allah be pleased with him said that, it was also reported in Saheeh Al Bukhari that Ibn Omer said that the Prophet salla Allahu alaihi wa sallam used to raise his hands in the positions you have mentioned. Therefore, the hadeeth of Ibn Omer is more authentic and must be followed. Having said that, it shouldn’t be a great issue as it is a Sunnah that a person would be rewarded for it but if he doesn’t do it, he will not be punished.