Okay, so I visited the Delhi T3 lounge recently and can confirm that there is no decrease in Lounge Queue during lunch hours.
Only Air India Business Class Lounge look impressive. Encalm lounge has a long line (wait time of 30 to 35 minutes that too when they have 3 entry points).
One noticable difference is that if you are claiming lounge on Business Class or Vistara Gold, then you don't have to stand in queue which is for the credit card users. However inside the lounge it is crowded as seats are not easily available as it use to be loooooooonnnnggg time back
Also I tried searching for Amex lounge but it seems they have sold it to Enclam.