I don’t think you can change the property used for the leaderboard in-game, so what you put in the leaderboard is permanent for the rest of the game but you could try to create another leaderboard/s using the text device. (blockcode)
In my opinion, I’d prefer Achievements + Coins or Coins Only.
I have one property set as Score, and two others, Achievement# and Coins. Score is currently calculated in the blocks by having Set Property Score; Achievement# * Coins.
The rest would be calculated the same way. How would I switch between the 4 just after pre-game.