I thought I'd be cool and try making some sub cuts with my cutter. The first couple of times went pretty good despite my strip sets not being exactly straight. Then I got greedy and to four strips instead of two:
I used a ruler to lay them out as straight as possible, put the mat on and rolled it through. Sort of. The roller pushed the mat over the fabric and everything shifted.
They are indeed 1.5 inch side strips just with a slight angle to them. I'm hoping they are still usable as I have to cut them down to size after they've been sewn.
I think I'll just stick to two strips until I can work with the machine more.