What you could do is do a linear pattern for the straight lines of the oval, and then use "Curve Driven Pattern" in >Insert>Pattern/Mirror>Curver Driven Pattern. The only thing is that feature only works with solid bodies so you'd have to convert the entites of the solid blocks and then hide the bodies themselves to just show the sketch lines. Maybe this helps?
Jasson, you can do that with a curve driven pattern.
1) create your slot-based feature and your pattern seed-features
2) create a composite curve from the perimeter edges of the slot
3)generate a curve-driven pattern of the seed feature.
I guess it's important to point out that you can't generate feature patterns of sketches or reference goemetry-unfortunately.