^ +1
Honestly, it would probably help food allergic consumers MORE to understand completely what they are up against. Unless you've worked in food service (and recently) you may really just not understand why some things work the way that they do.
In most places, kitchen staff is bilingual... or does not have good English literacy.
So a chef card, a conversation, etc. is all useless unless you have someone translating in real time.
The level of motivation to handle food allergies is utterly idiosyncratic, in my experience. It varies too widely to generalize. We, like Mac and her family, eat out a fair amount. But we choose our restaurants with risk in mind, (based on the menu) and are still reliant on our gut to tell us whether or not a particular occasion/server/etc is giving us a bad vibe or a good one.
I also completely "get" wanting that conversation or management to not be front and center, for it NOT to be the center of attention for one's companions, etc. Unfortunately, unless you do a ton of preparation up front, that's not realistic. We've done that, by the way, for one-time occasions where DD (or myself) really needed to be non-obtrusive in a particular setting, but it's not easy and it takes a LOT of time and cooperation from the food service staff. How does that work?
1. call ahead-- OUTSIDE of rush times-- and ask to speak with the manager who will be on-staff and managing the kitchen staff when you will be there (in a week, a few days, whatever)
2. explain your allergies, and ask questions-- make a plan for what you will order and how you will communicate with your server at the time, how kitchen staff will be instructed to handle your meal, etc. DECIDE whether or not this is "safe enough" in your estimation, or
3. Thank the person for their time and explain that you will probably NOT be ordering food, but may order beverages (again, comfort zone and past history taken into account).
Otherwise, a chef card is about as good as it gets-- but just understand that even if your server can read it and understand it, that doesn't mean that the kitchen staff can.