Just checking, are the instructions backwards? When the key is turned in clockwise the spring is compressed, higher vacuum needed to start advance. When it is turned out counterclockwise, it is decompressed, lower vacuum needed to start advance.
No. CCW compresses the spring, CW relaxes the spring. When the spring's compressed, it's harder to compress further, causing more vacuum to be needed to compress it further and give advance. When the spring is relaxed, it allows the advance to come in earlier. That's how it's designed. I've always said the vacuum can controls "when" not "how much" as hoppy explained.