Unclued lights form a progressive set, plus the name of the speaker.

Across

1 Talk shortly about present-day veg (7, two words)

6 Secure trim accessory (7, two words)

11 Harp on about poor child (6)

12 Sun already, so? It’s a feature of India (7)

14 Welshman and Scotsman clash over nymph (5)

15 Console unknown author about chapter (5)

16 Delicate and light, keeping in time (6)

19 Chemical from Chile in unstable radon site (9, two words)

21 Embraces and fondles lasciviously (7)

24 From memory recalled dry poem that sends a message (9, two words)

...