In the way one member can send acorns to another, would it be fun if one member could send a badge to another member? Maybe a member who is really excited about their new rose bush could be sent a rose badge if they don't already have it. Things like that.
Maybe some badges just for the purpose of being sent and received, in a separate category from the ones that require purchase via acorns? Maybe some things like a "so sweet" heart, "you crack me up" laughing face, "great idea" exclamation point, something for sharing great pics, something for being inspirational, a special thank you, clapping hands for a standing "O," whatever members might enjoy "awarding" to each other.
Maybe badges could have a counter attached so you could see how many times somebody sent the particular badge to you, the way it shows how many thumbs & acorns have been received.
It seems like it could provide another interactive aspect to the fun here, if there is an interest and somebody wants to set it up.