Every AI I've seen through II was a poor deal and almost always as expensive as getting the same resort not using an II exchange for the room, all included AI options and air flights. There was one exception from years ago but it was never available for exchange. There's a reason that a lot of resorts go the AI route, it's very lucrative for them. Even for the ones that are optional AI, make sure you investigate well to be sure there aren't other gotchas. What I have seen over the years is an occasional resort with an optional meal plan though I don't know of any currently. The one's I've seen and either considered or purchased were flexible across multiple people and for as many or few credits as I wanted. Basically I could buy it for an occasional use and potentially use it for more than one person. In some cases, sharing though not for buffets. Of the ones I've used either they no longer have them and/or have changed management since.Be aware if you book AI through Interval you have to pay the AI fee to the resort yourself, in addition to using y our points to make the exchange.
In most cases it is best to book an AI directly or with a getaway or such, not use your points.