The ramifications of this do go quite some way: the swastika symbol was used as national markings in blue by the Finns, and in red by the Latvians for a while; and all over the shop in its good luck symbol form. If the 1920s-30s market was bigger, the issue would be even more prominent. For myself I've noticed swastikas eg. on the wheel hubs of FAA planes.
A little more back on topic: the contortions they go into with decals can be frustrating. I'm looking forward to building Roden's ski-equipped SPAD VII, but of course one option is a Finnish machine. Unfortunately they decided to provide two 'crooked S' shapes to make up each swastika, which means double thickness blue in the middle. Not too difficult to remedy, but still.
As jknaus points out, the actual Nazi swastika was distinctively oriented at a 45 degree diagonal. I guess it's inevitable that the ban had to cover all swastikas. But I've just picked up a Special Hobby Fokker D.XXI in Finnish markings, and wouldn't you just know it, while the decals are ingeniously split up into jigsaw pieces, the box cover painting plainly shows the correct blue Swastika on the side of the plane.
Mark