Seems like you could detect if this was important or not. If it is the first or last word it is as if the user is talking to you and you can strip it; if not it's not.
It's very naive but worth looking into. Could always test this if it is really costing so much money for one word. Or build another smaller model that detects if it is part of the important content or not.
There are hundreds of other opportunities for cost savings and efficiency gains that don’t have a visible UX impact. The trade-off just isn’t worth it outside of some very specialized scenarios where the user is sophisticated enough to deliberately omit the word anyway.
