I still like the idea in general, but here are some possible problems to consider and some further thoughts on the "open invite pairs" option.
I assume the current "open invite" procedure would not change. The "pairs" option would just be added to what is now available. We would be able to specify rating limits, create rated or unrated games, etc. in the "pair offer" games as well.
I am also assuming that the pair offer would appear as a single line entry on the "open invite" page, and it would somehow specify that it represents a pair of games, to help avoid confusion. Perhaps in the "color" column it could say "both" or "one of each" or "pair of games". Also someone could create a new icon for "game pair", similar to what is there for the "set-piece" games if that would help set the offer apart from single games. Or a window could pop up when the pair is selected, offering a brief explanation of what this pair offer is.
If the pair option is added as a single line entry and you are required to take both of the games when you take up the offer, there is currently nothing to prevent you from then deleting one of them when they are on your "my games" page. What would happen then?
The current open invite system places a deleted game back on the open invite list. What happens if someone picks up the pair offer then deletes one game when they go to their "my games" page? Would that deleted game go back on the open invite page by itself instead of as a pair offer? Would it be lost in cyberspace, or would the software crash?
Also, deleting one of the games would be contrary to the intent of whoever created the open invite "pair". If they created the "pair" offer then that is what they wanted, to play two games against the same person. Otherwise they would have just put up the usual regular open invite game in the first place.
The "pair" games could be coded differently and be treated as a tournament game so they could not be deleted. However, the automatic timeout feature of a tournament game would also have to be disabled.
What about people on your "ignore list." I'm not familiar with that feature personally, so please correct me if I'm wrong about this! If you have someone on that list, I think they cannot pick up an "open invite" game from you. However I also think if you are both in the same tournament there is a possibility you may have to play a game against them. How would that be handled with a "pair offer" if the games are coded as tournament games to prevent someone from deleting one of them? There may need to be additional code for the ignore list, since the pair games aren't really
I still do like the idea in general, but adding the option to put up an "open invite pair" would probably be a programming nightmare and more trouble than it would be worth. It would only add a minor convenience and would be nice for that reason. But currently, when you offer a single game there is nothing to prevent you from challenging your new opponent to another game right away, with opposite colors. Now you would be playing that pair of games against the same person and it was easily accomplished with a minor effort and the same result!