If we were to find another way to handle the search index, then yes. We might be able to figure something out.
Alternatively, the resource hit would be a lot less if you were using Sphinx. So someone could create a modification to handle this if the user is using Sphinx I suppose.
Because of the resource implications, it's doubtful we will add such functionality in the near future I'm afraid. We have customers will millions upon millions of posts and the software should work just as well for them as it does for the boards with a few hundred posts.