I'm building a AUR wrapper and I would like to display the package groups next to the search results when someone searches for a package like pacman does it for official repos. In the wiki  it says that the output of the aur rpc is just a list of info request outputs. But when I'm doing a search  I don't get the extra info I get with a info request . What I would need is the "Groups" info. Could this be added to the list of elements that a normal search returns? It would speed up my wrapper alot. Atm I'm doing info requests for every single package that I get in the search request and I really don't like that. :/
You can use the multiinfo interface, which should allow you to at least perform one request per 150 packages, instead of one. Adding arbitrary fields to the search interface is something that's unlikely to happen.
An ideal way would be for clients to access all available AUR metadata. There has been some discussion about this in the past (suggesting the use of zsync).