Originally Posted by
LowObservable
Speculation, but would tip vortices on most fighters get somewhat suppressed by pylons inhibiting spanwise flow?
depends.
pylons mounted well aft of the LE won't act as a vortilon, but some that are closer to the LE will. Stores that extend forward of the wing LE will at various AOA start to generate vortex filaments that may rise above the wing and that can alter span wise flow, which will suppress the tip vortex. The vortex sheet rollup off the span of the wing TE will still roll up eventually being mostly drawn into the tip vortex filament.
Vortilons & external stores increase RCS almost always, but, flow modifiers can be employed that do not alter RCS appreciably.