I’d do the A levels if I were you.
As Scroggs said, you need something to make your CV stand out - if you’ve got no work experience to talk about, it will have to be qualifications. The more the merrier!
I’d also recommend doing them as a ‘plan B’ in case you ever lose your medical. It happens more than you might think, and it would be nice to have some bits of paper to fall back on in case you have to apply for ‘normal’ jobs.
(I found A level physics quite useful for the ATPLs by the way).