In the "old" days, when stippling was usually done by hand, it was easier not to cross over, so there was an unwritten rule that you don't cross.
With todays machines, that really doesn't apply anymore.
The only time I would be concerned is if I were making a competition quilt. The judges could be picky, if it came down to 1 point, and 1 crossed over and 1 didn't, they might choose the one that didn't.
I agree with everyone, it's my quilt, my way.
Just enjoy