You've been caught, sweetie

I sent six puzzles to the Times but received the following reply:

Dear Sir,
We are sorry to reject your sequential crossword submissions for the following reasons:

• The squares must be 15×15 or 21×21
• Words cannot be duplicated
• Odd nonsense words are undesirable

Sincerely, The Editor

I was going to try the Sun instead, but misplaced them. All I have are the titles!

Can you reconstruct them? Also, please use the result to answer the following question:

What are you if you spend too much time on PSE? (7)

Helpful note: Series ascends to one result. So this is ultimately doable. But if your head is muddled, get some sleep and try again later.

Crossword Puzzle Titles:

• Atop Nobelium

• Duo attack rocks

• 2.4 note mtg. change

• Fortissississimo watcher and supreme duplicate currency

• 5th-gen wireless block vendors & wasp colony, nimble overhead

• 666666 foul Ganymede titans optimize web traffic – you’ve been caught, sweetie, _ _ _ _ _ _ _

Hint