This sketchy Venn diagram shows 12 Reformed Conferences and something of how those attending cross over. Most are ministers conferences but the four in yellow, red, orange and pink are aimed more broadly. I am conscious that this does not include Word Alive or Keswick. (The Affinity Study Conference is only every two years). I'm sure I've missed one or two other conferences such as the EFCC ones.
Bonhoeffer uses a similar phrase 'worldly Christianity'. It's J Gresham Machen that I want to line up most closely with. See his Christianity and culture here. Having done commentaries on Proverbs (Heavenly Wisdom) and Song of Songs (Heavenly Love), a matching title for Ecclesiastes would be Heavenly Worldliness. For my stance on worldliness, see 3 posts here.