Trainee to track upgrade

[ForZiE23]

Currently trainee but planning on upgrade. Track wise i feel confident enough and done the dates required plus some. Now the upgrade is a two part, track and flagging. I have done 3 days flagging but its this part of the assessment which i think i am currently nervous to upgrade. I enjoyed flagging but ultimately think for now at least incident is where i would like to stay. How confident or correct do you need to be to allow passing this part of the upgrade? i can show my understanding of flags ok, wave them OK but also have the should i / shouldnt i with the blue on some situations. Welcome feedback on it as all the IO's recently have suggested i should start looking to upgrade soon but would like to make some dates for this.