This latter question probably belongs in Meta, but as a random bystander's guess: I expect them to happen in Character Builds & Optimization. That there aren't any now is probably not because that forum is somehow restricted. It's probably because the game isn't even a month old!!If so, where will they end up? The Character Builds & Optimization subforum here on enworld seems to be only for D&D so I didn't want to post this question there.
Either you are looking to multi-class, and are planning to get a Dedication feat.... or you don't, so...?Suddenly occurs to me that, ironically, if you are not looking to multi-class generally that Cantrip Expansion is a bit of a trap option. You will pretty much always be better off getting a Dedication feat for Cleric, Druid, or Wizard than you will just getting Cantrip Expansion if you can afford to start with a 14 in the appropriate stat. I was thinking about this because potentially if you are an Arcane Sorcerer and get Wizard Dedication at level 2 you are getting a two level head start on collecting spells for when you get Arcane Evolution at level 4.