Even breeding the erythristic het goldens to each other will produce variable amounts of erythrism and some will be practically normal or golden, but will never be pure golden only. From that breeding approximately 25% of the babies will be golden the rest will be normals, and all will have variable amounts of red. So even within the babies that are goldens they will have various amounts of additional influence from the eyrthristic flame.
Hope that all makes sense.
This is based on past knowledge of how these genes behave, yet who knows what the extreme end of the erythristic flame golden will look like. I think it will be a glowing solid orange snake with tiny black flecks. IMHO this could potentially be the most awesome looking garter snake ever produced, but everyone has their own opinions and different color and pattern preferences.