Can we get a "max path weight" optional param for a_star_search?

Maybe there's another workaround.

I have a situation (I'm working through the tutorial book) where a monster can _see_ me, it's physically _near_ me, but it can't _get_ to me (typically because another monster is in the way). Like, at all; no path exists.

So it runs an A* search, and sometimes that search (depending on the size of the map and some other factors) can take seconds! It drags the game to a halt. But really, even if the thing found a (super long) path; I don't want it to take it. So what I'd like to say is, find me a path with max weight <= 20, but if not, like, go about your business. But that doesn't seem to be possible at the moment.

Based on my (partial) understanding of the A* search algorithm, this shouldn't be a significant change. Is this a reasonable thing to add? Is there another workaround that I just don't understand?