A scholar who is a Hanafi says that Nafl Salaat in Jamaat is permissible.

Answer

The fellow is a dumb 'scholar'. According to the Hanafi Math-hab, Nafl Jamaat is not permissible. We are Hanafis, not Hambalis. Al-Mughni is a Hambali kitaab. The character who quoted from Al-Mughni is a freelancer, like the roaming holy bulls of the Hindus, who is unable to distinguish between right and left. He dwells in the darkness of nafsaaniyat. He should concentrate on the rudiments of making Istinja properly, then only will he be able to understand Ahaadith and the principles of the Shariah.