Curious how you handle the airborne seafood one since even at a private table there will be tables around yours. Are those people informed that they cannot order seafood? I'd be pretty livid if I paid money for a cruise and was told "Sorry, because you got the luck of the draw to be at a table next to someone with an allergy, you cannot order anything from this food group." (Seafood would not be an issue for me because I find it disgusting anyway. But a lot of people would want it.)
No, the tables around us can have whatever they want.
When we work with Special Services i n advance of the cruise, we ask for a table away from others/that has better ventilation, and try to sit at the table in a way so we are as far away from others as possible. An example on our last cruise -- in Royal Court we had a round table that backed to a wall and to one side a pillar, so there was actually several feet to the table to the left and a few feet to the table to the right, the wall behind, and no table directly in front (it was the "right of way" walking path to get to the left hand table and to the serving station). I sat against the wall as far from each table as possible - we moved the chairs a bit. In Enchanted Garden we have been put in tables along walkways and in corners. So, tables with "natural" buffers to others. Not seated next to the serving station.
Also, the airborne reaction doesn't get noticeable or severe enough until some (unknown) threshold gets hit -- so a Red Lobster restaurant is a no go (can't even get past the front door), but an Outback is usually manageable. Most of the time in the MDRs we are mostly ok, but I have had to leave once mid-meal due to a reaction and our serving team recommended we skip the MDR one night because it would be worse than the night I had to leave (it was 2 nights later - lobster night, when "everyone gets the lobster"). Our serving team arranged for our meal to be brought to our room for that night. Most of our cruises have been on the Dream so it has not been as much as a problem as on the Fantasy.
SW