Brep-plane intersection component: is there an advantage to preprocessing input?

I thought I’d be smart and preselect only the breps that cross the planes I am using to take sections, but it seems like there isn’t a significant speed improvement when I do this.
What’s going on here, is this because the brep-plane component already does this check much faster than my own grasshopper method? (5.1 MB)

Yes it performs this check by testing whether the signed distance of the eight corners of the bounding box to the plane are all either positive or negative. This is very similar to your check except it works for aligned section planes as well.