Hi Turro,
there should be no changes in master branch which have slowed down the imports. Do you register that importing got slower or are you importing bigger shapes bigger than before ?
> Multiprocessing/Multithreading: May be better, i have to check how good this works with FC.
> C-code: Sure faster, but i have no idea about implementing it into FC.
Additional:
I am working on a big update within the devel branch. A2plus creates "xxx.a2p" files during importing of files. The files contain all resulting work of an import process (shape, colours, toponames) and speed up a second time import by factor 3-4.