Pope Benedict XVI, in his book, the Spirit of the Liturgy, viewed the orans position in a positive light. Unfortunately, I’ll have to dig up the quote because my pastor still has the book. It would be nice to use the orans posture; however, in my neck of the woods, some folks would see it as an automatic invitatino to hold hands.
Now, I think that there are certain postures one should not take while up there with the celebrant. The best rule of thumb is to observe what the ministers do at a Papal Mass. If you notice, the only ones who extend their hands in the orans posture are the Holy Father and his main concelebrants. The deacons do not. Msgr. Guido Marini, who is the Papal MC, does not. He and his co-MC keep their hands folded. Even the seminarians who are assisting him keep their hands folded as well. Now, the rest of the cardinals, if they are vested for Mass, will either adopt the orans posture or keep their hands folded.
I’ll have to double check on the rubrics, but, I think that the stipulation would apply if you are serving at the altar. I could be wrong.