Thank you for your post.
There are two ways you can control the section hatchings, which are:
1. Create a material and add the pattern you want then select the scale/size of the pattern.
2. Use one of the existing section hatchings. To do this go to the In Model section (click the home icon) of the SketchUp Paint Bucket once the hatching has been used in the model, then select the pattern you want to change and click the 'Edit' tab and it will allow you to change the size and colour of the hatching.
Would you be able to please let me know if these work for you?