Any practical effect felt at surface underneath 'weaker' South Atlanic Anomaly (SAA)?

semiotically

Does the Van Allen Belt dipping closer to the earth at the South Atlantic Anomaly mean the earths surface underneath (like South-Eastern Brazil) is more exposed to solar storms..?

My terminology might be slightly-off here: do Singular proton events (SPEs) affect the SAA area more as the magnetic field is weaker & so the protons remain concentrated here. If SPEs affect the ozone reducing it & combined with less distance (closer) to begin with would these lead the SAA area more vunerable to (successive) solar storms (e.g. CMEs)?

If this seems a long shot it’s because it is! Please direct or recommmend me reading...
Thanks

Secondly...

Does the GeoDynamo Theory of the earths magnetosphere still carry general consensus? I read briefly the concept of 'magnetic integration' whereby the fields generated only at the earths surface integrate into a global field - I found this quite elegant...