the only time your stitches should not touch/cross in machine quilting is when you are stippling- a stipple never touches, crosses- free motion meandering crosses, does loop-de-loops, hearts, stars, flowers, leaves, feathers....what ever
in hand quilting it was always a *rule* that stitches not cross- had to do with them wearing away each other...that is no longer the case- with machine quilting- unless you are stippling- then they should not---that's the pattern- if the pattern causes cross overs it is expected.