Hey JL,
ATP exams are now written the same as Com. That being you have unlimited attempts, and can write one at a time. You still only have 18 months to complete them though from the date you obtain your first credit.
With regards to Plotting.. it was decided at the last DE conference that it be scrapped with immediate effect. However, I've still yet to see formal wrtitten confirmation of this anywhere. So if anyone out there knows more about this... please advise.
Ciao!