I think that, at most, we just need to reinforce the theme of Gold. I think Vera has worded it nicely. I see it as the place where mixers and corpies overlap most.
Mixers can visit many of the recreational and professional spots there (though there a few corpie only venues). Mixers have business they have to handle there - doing so on Red is just not an option. Corpies have to go there for their work in most cases and also for recreation and shopping and whatnot.
I feel that the streets of Gold should not feel super safe for corpies and they generally don't. Mixers should be worried about getting harassed and they sometimes do. A mixer with fines or bounties should feel super nervous as they are more actively sought.
Corpies on corporate property should feel safer and safer still on their own property. These places should make a mixer feel a bit more vulnerable. I feel this happens. With a few exceptions, the WJF's main concerns are the streets, public places and businesses that can't or don't field their own security force.
Gold is very busy so, while there are a lot of Judges, they are not going to show up instantly. If you take the time to plan your crime, you can get away with even fairly blatant crimes. If you plan poorly (commit a crime right by a Judge or other security) you will have a hard time.
I know people want there to be interactions between corpies and mixes. And, in my experience, there is. It's just not done openly and I think this is as it should be. Even if you extended the mix to include Gold you still wouldn't (and in my opinion shouldn't) see corpies and mixers colluding in public places.
So I urge mixers to be open to spending more time on Gold. To be less judgemental of other mixers who spend time in gold. I encourage Corpies to actually go to work in Gold and to engage in recreational activities and shop on Gold. Engage other corpies down there. Maybe band together for safety. If you are a bored corpie who wants to see some action, expose yourself on the streets of Gold - be a target.
I encourage WJF PCs and CorpSec PCs to think about creating interesting story when dealing with mixers on Gold. It's not like Green or Blue. Read the ambient room descriptions on Gold and compare them to Green for example.
To me the Red is a poor and destitute slum. Gold is like the down town portion of a large city with high crime rates. Parts are clean and golden examples of Corporate living and power. Patches are darker and frequented by mere shady individuals.
Being a mixer does not have to mean only ever being in Red. You can be a mixer and spend most of your time on Gold just fine. A lot of employees on Gold ARE mixers.