This pattern originates in search for an answer to a question: How should one make symmetric socks from leftovers without too much troubles while following the same colour sequence for the second sock and without weaving in to many ends. The method suggested here is one way of solving both problems. But it has its price. Two steek cuts have to be sewn.
The pattern contains several different techniques. However, if one wants to benefit from the original idea - how to use leftovers - just skip the complications.
Finally, the pattern is free and will remain free. It was not tested. Therefore, all comments are more than welcome.

Sept 1st 2022
Thx to comments of emilymcrae and her brave work on the socks, the pattern was corrected at few points and few points were made clearer (hopefully). The new version was uploaded.