5th A-Level

Hi guys , hope you are well. In September i plan to go to uni to do economics, however if the first semester is online, I'm gonna defer my entry cuz only going uni for the experience and qualification, the content I can just find online. In this year off I will ofc keep up my economics, but I may also take a course in Physics or something else challenging to keep me learning. I was wondering if I would be best to take an A Level in this subject, so in turn I would have 5 A-levels (which is useless) and have something to show for my learning, or just learn it myself and don't receive a qualification for it. Ofc I would have to pay for a) the exam entry fees and b) some sort of tutoring (Uplearn is 120£ for the OCR course. After economics at uni I may choose to go into a career that knowledge of subject like physics may be very helpful. I did get a 9 in physics at GCSE and expect A* A* A B at A Level so although I expect it to be very hard, it would be doable. I did maths in one year in year 13 alongside the 3 other a levels. What are your guys thought, theres no right or wrong, should I do an A level in it or just teach myself without gaining any qualification for it.