Is the two-rak'ah "Tahiyat Al-Masjid" (greeting of the mosque) prayer forfeited for someone who enters the mosque during the Friday sermon, or should he pray them lightly?

If you enter the mosque during the Friday sermon, pray two light rak'ahs as a salutation to the mosque, and then sit down. This is based on what was narrated from Jabir ibn Abdullah, who said: "Sulayk al-Ghatafani came on a Friday while the Messenger of Allah, peace and blessings be upon him, was delivering the sermon. He sat down. The Prophet said to him: 'O Sulayk! Stand up and pray two rak'ahs, and make them light.' Then he said: 'If any of you comes on Friday while the Imam is delivering the sermon, let him pray two rak'ahs, and let him make them light.'"