Well, Terma has developed the gun-pod and a "multi -mission" pod with the same mould line.
Terma has delivered more than a 100 Gun Pods for the F-35 Lightning ll, the only certified external pod for the F-35 fighter jet. Terma is now introducing the F-35 Multi-Mission Pod – a further development to the Gun Pod, providing additional mission payload volume for the platform.
www.terma.com
So that shape would theoretically let you carry one NGJ-LB or -MB on centerline with an acceptable signature effect. Beyond that you'd have to talk to LM about a specific shape for underwing stores.
We know they have been at work integrating IRST and fuel pods for the Raptor. It'd be pretty surprising if work hasn't taken place at least exploring stealthy ETs and such under their best-seller.