Considering dropping EPQ or Chemistry.

Currently doing Maths, Physics, FM and Chem + EPQ. I've realised that I don't have enough time especially with outside school activities and it will affect my academic performance doing all this. Realistically, dropping chem would make life so much easier, and I don't think that 4 a levels would give me an advantage over people doing 3, right? Also apparently the EPQ may be able to lower your entry requirements at unis.

I hope to study mech/aero engineering at Cambridge, Imperial or UCL in that order, so my question is, do I drop chem and go down to 3 a levels with the EPQ, or drop the EPQ and stay at 4? Lmk if I should give more context or info, ty.