It really depends on whether you can balance it all or not. I did 4 A-Levels and an EPQ (in mathematical philosophy) and tbh, though it was a lot of work, I thought the EPQ was quite valuable to me. Not because it reduced my uni grade requirements, but because it was genuinely enjoyable. If you're already stressed about A-Levels and are not fully passionate about your EPQ, then I would probably drop it.