I think the format of this contest is not correct. If only 5 bets in each round to be considered then there will be lots of draw for three positions. How will you determine who are top 3 if say 10 participants get 10p in this round?
Why not allow unlimited submissions if someone reaches top of the tower and 5 if someone fails to reach to the top?
You are right. Who wins the prizes comes down to who sees the thread first.
Players will compete if the basis for deciding winners is changed to best five of submissions with highest won amount. 10p for $10 won in 5 bets of 0.1, 11p for $11 won in 5 bets and so on.