Dimensions should come from main accounts default values to interest notes. 

If there is “not fixed” or “fixed value” defined, it should bring those to interest notes. 

Now it seems that dimensions come from customer Master data and it overdrives main account default dimensions. And if there is not defined any dimensions it won't check dimensions from main accounts when posting. 

We want dimensions to come from main account default values if there is any. And cases when there is “not fixed value” it should bring that dimension what it’s defined there to come if there are not any dimensions defined on the interest note.