jaedarph : thank you for the C8 patch, I didn't know it existed. It fixes few annoying problems, but the anti-aliasing option doesn't work :-/
But, but, but, I found a solution :-))) : I export the map with a great size (5000px for example), and after, I reduce the size of the jpeg file (with Photofiltre). The texts are readable, the line are smooth, no scales, no need to add blur effects on all the sheets (or almost), no need to add the texts with an other software ... houra !!!