Further Maths and normal Maths A-level module swaps (edexcel)

Hi all,

I'm self teaching edexcel further maths full ALevels in my gap year. (This academic year)
I've already sat normal maths where I achieved 90 ums in S1.

Will edexcel allow me to swap my s1 result from two years ago with my lowest result this year in further maths (not FP1 or FP2) such as D1,D2 S3 and S2? This is assuming it doesn't affect my normal maths result (which it shouldn't considering I achieved 540/600)

For a module swaps to occur do they have to be in the same academic year?

Thanks!