I scored 18/24 on the Arctic Shore tests on the 14th. I was assigned to Stage 3 on the candidate portal and then moved back to Stage 2, yet I have not received a mail from J2 since the original test. I can imagine that they're making their way through a lot of people and it's probably not simply a x out of 24. Each section may hold slightly more or less weight with it being more relevant to the role etc.
Like all of these, it is a guessing game unless you are in the recruitment team.