Dropping 4th A-Level after offer?

Context: Reapplying in gap year whilst retaking Maths, Physics and learning FM, got an offer from Bath for Pure Econ and they said I could drop FM.

Achieved: A (Econ A-Level), A (CS AS Level) + A (EPQ)
Retaking with predicted grades: Maths + Phys (A*), FM (A)

I feel like dropping FM due to the amount of workload possibly affecting specifically Physics, but im unsure if I should drop it now or after getting an offer (even though I doubt I will get one) for UCL PPE and Durham Econ + Politics.

I am quite confused about how UCL will look at my appication; they say they look at the 3 highest A-Levels and ignore the 4th one but I am not sure what my 4th one would be as my Econ and FM grade are the same. I guess it would come down to the preferred subject they want but most univeristies for Econ courses do not really require Economics at A-Level but neither is FM a requirement especially for PPE despite seeming Maths intensive. Also FM is predicted whilst Econ is achieved which could give more weighting towards the Econ grade?

Also do not know how Durham would take it. I'm so lost lmao

You cannot drop the A level without the universities approval. They made you an offer expecting you to take 4 subjects. You would be breaking the contract you made so they would be entitled to change or withdraw an offer. That is the strict position but to avoid any problems get permission before dropping a subject. It is extremely unlikely any university will care.

To meet your offer terms all you need is to turn up for the exam. You dont need to pass the exam or get a certain grade and you will meet the agreement.

Wait and see if you get an offer and then ask them about dropping it before you pick your Firm and Insurance.

Yeah I'll just wait and see what the outcome is even though they're being quite slow

Although, as stated in my earlier reply, I'm really confused on how UCL sees my application specifically since they only consider the 3 highest A-Levels applicants have. FM and Econ both have the same grade (FM is predicted but Econ is achieved) so I'm wondering if they will consider both, or only consider Econ, or only consider FM.