Prolonging the last sujood is an action that is not prescribed in Islam

It is not permissible for
the person who is praying behind the imaam to precede the imaam. It
is haraam for him to move before the imaam, or to lag behind him so
much that he misses the obligatory part of the prayer that comes next.
The Prophet (peace and blessings
of Allaah be upon him) said, “The imaam has been appointed to be followed.
So when he says ‘Allaahu akbar,’ then say ‘Allaahu akbar,’ and when
he bows in rukoo’, then bow in rukoo’.” The conjunction fa’ (translated
here as ‘then’) implies following immediately, as is well known [in
Arabic grammar]. 

Shaykh ‘Abd al-Kareem
al-Khudayr 

The idea of perfecting
the prayer does not contradict the idea of following the imaam, so long
as the imaam is unhurried in his prayer. There is no evidence for singling
out the last sujood and prolonging this sujood but not the others, and
it is not permitted to introduce innovations into the religion. And
Allaah knows best.