Back to the question of “raising of the hands of the faithful after consecration”. It is certainly not allowed - it is the “orans” postion, which at this time in the Mass is reserved for the Priest.
As to why some Priests allow it, I don’t know. Some Priests don’t pay attention to the GIRM and just choose to do what they want and encourage their Parishioners to do the same. Some Priests are disobedient like the rest of us, they are human the bad and sad thing is they lead others into their disobedience. Pray for all Priests, they are far more culpable for errors in the Mass and other Church teaching than are we, the lay people because we are expected to obey them. We should do our best to learn the truths but it is not always possible, especially before the internet became widely available.
I have to tell you that I have to practically clasp my hands together at this part of the Mass, the Consecration because my hands want to go up in praise of Jesus being present now. I don’t because it is not appropriate for me to do so.
I also need to point out that this position is very Charismatic, not just Evangelical Protestant (does that help define it more for those who are or were Protestant and didn’t do it in their old church?)
Brenda V.