Are the current shorelines of South America and Africa accurate representations of those continents when they were rifted apart? What factors other than rifting and seafloor spreading could have modified the shape of the current shorelines?

Yes, they were believed to be modified by the formation of the rift valleys and volcanoes activity.

Explanation:

The theory given by the Alfred Wegener provided evidence of the drifting of the continents and the formation of the current shoreline with the respect to the breakup of the super landmass and thus the shorelines of Africa and those of South America are an accurate representation of the breakup and the drift The several factors are accountable for the nature of the coastline that has modified the shape and the size of the continent includes the formation of the rift valleys and the geologic and the tectonic processes and the presence of the faults and the folds in the history of the earth crust.