Answered by Shaykh Hamza Karamali, SunniPath Academy Teacher
When following a Shafii imam who recites the qunût during fajr prayer, what should followers do? Should they raise their hands and make duâ? Does this change if the qunût is inaudible? If one is praying behind a non-Shafii who does not recite the qunût, what should one do?

In the Name of Allah, Most Merciful and Compassionate
Preliminaries
A related question has previously been answered on the list and is available at:
The Shafi`i Qunoot
When Praying Behind a Shafii
When one’s imam recites the qunût, one should raise one’s hands. If one can hear his recitation of the qunût, one should say “âmîn” after the portions of the qunût that are supplications and repeat the portions of the qunût that are praises.
For example, when the imam says, “allâhumma’hdinâ fî man hadayt,” (trans. “O Allah! Guide me among those you guide”) he is supplicating Allah for guidance and the follower should participate by saying “âmîn” (trans. “O Allah! Answer [the supplication]!”). According to Ibn Hajar (Allah be pleased with him), sending blessings and peace on the Prophet (Allah bless him and give him peace) is also supplication after which the follower says “âmîn”.
When the imam says, “fa innaka taqdî wa lâ yuqdâ alayk,” (trans. “ for You decree and none decrees against you”) he is praising Allah and the follower should participate by repeating the formula to himself by saying silently, “fa innaka taqdî wa lâ yuqdâ alayk.”
If the imam’s recitation of the qunût is inaudible, one should raise one’s hands and recite the qunût silently to oneself.
One should not wipe one’s face or chest after the qunût.
When Praying Behind a non-Shafii
If the imam does not recite the qunût, then one should recite the qunût silently to oneself. It is sufficient to recite a minimal qunût such as, “allahumma’ghfirlî yâ ghafûr allâhumma sallî alâ sayyidina muhammadin wa âlihî wa sahbihî wa sallim.” If one limits oneself to this du’a, one should be able to continue the prayer without lagging behind the imam. In any case, one must catch up to the imam before he starts going into the second prostration. If this isn’t possible, one should omit the qunût and simply follow one’s imam. Note that the qunût is not an integral, so omitting it does not affect the validity of one’s prayer.
Whether or not one recites the qunût, it remains sunna to perform the forgetfulness prostrations after the imam says salams to compensate for his not reciting the qunût. The forgetfulness prostrations are, however, sunna in the Shafii school and hence if one is apprehensive about how the congregation will react if one performs them, one may safely omit them without this having any effect on the validity of one’s prayer. Furthermore, raising the hands during the qunût is a sunnah (hay’a) that doesn’t need to be repaired (by forgetfullness prostrations) if omitted. If one chooses to omit it so as not to distress or confuse others in the congregation, this will not render the prayer deficient.
Sources: Reliance of the Traveller, f8.53; Tuhfat al-Muhtaj, 2.67-68, 2.171.
And Allah knows best.
Hamza Karamali and Moustafa Elqabbany