Question about Penalty Clash

I’m planning to invest on a prospect in Penalty Clash event this season and I haven’t checked it for months, so I want to ask for some information about how this event has changed so far. For f2p players, what is the furthest point you could achieve in it and what is your strategy? For those who purchase the offer that allows you to skip the progress to level 20 if I’m not mistaken, how far could you go in the game and what are the strategies you apply? I have played the event twice but in both times I couldn’t play in the last day due to my personal works so I cannot estimate how far as possible I can reach. Thanks in advance.