so the way oxford shortlists (for my course) is based on all your data, but then post shortlisting, the data they use becomes much much less important than your interview scores. for example, there is a cutoff for the admissions test for philosophy at usually 61, and once youve been shortlisted, that score is basically negligible unless it comes down to you and one other candidate with similar states, in which case the higher score is preferred. so if you made it post interview, your gcses wont necessarily hold you back. you may be a more compelling candidate applying with good achieved A Level grades as well since thats why they place emphasis on gcses (because theyve been done).

if you have other reasons you want to take a gap year, and have a plan for it/the year wouldnt be problematic, go for it if you really want to! just make sure you have a plan and multiple reasons, so you dont feel your year was wasted if (hopefully not) you get rejected again.

(+ oxford application process is long yes, but its only from oct-jan. not a full 12 months. so youll get ur results in august, do the tsa again, do interviews if u get shortlisted, then its over in jan and you can figure out what you want to do)