To increase the grip when working with a small surface (where a rail or straightedge is hard to work with), I have tried two methods:
1) Adhere sandpaper to the fence
2) Spray an anti-slip coating (for stairs, steps, etc.) onto the fence (mask the window before you spray) (https://www.homedepot.ca/product/epoxyshield-epoxyshield-anti-slip-clear-340g/1000785172).
Method 1 would throw you off on the fence depth setting by the thickness of the sandpaper. You can apply the sandpaper when you need to use the intersecting-line technique, and remove it afterwards.
Method 2 is my preferred method as the coating (2 - 3 light coats worked well for me) does not seem to affect any setting. The extra purchase works for regular operation as well, not just for the intersecting-line operation. If you want to remove the coating for any reason, use mineral spirits. Try this on a metal surface if you aren't sure, and follow the instructions on the can.