If you believe that certain rubrics in one rite are more correct and ancient than the other **you have an obligation to not follow modern incorrect rubrics. **
There are many good people who simply do not understand or appreciate the deep damage that was done by the interruption of our constant worshipping tradition in the Latin Church. I often express it quite simply: if you were to line up the twenty-two or so different rites of the Catholic Church and look at them dispassionately, one of them, in the way it is celebrated, the use of secular styles of music, etc., stands out like a sore thumb for its diminished sense of awe and transcendence: the contemporary Roman Rite. By 1970, the Mass had become a sort of consecrated karaoke hour, an amateur show in which the liturgical rite was shaped to express the theme of the moment… NOT something to be gratefully received, reverently celebrated and entered into, and faithfully handed down. The Liturgy should shape US, not the other way around.
If you are for example accepting the holding or raising of hands during the Lords Prayer this would be a mistaken innovation unknown to our ancestors. Also to willingly accept the Versus Populum instead of Ad Orientem is an abandonment of apostolic tradition.
God is merciful but at the same time to stand up for ancient tradition once held in common by the entire church is our ideal.