The driver itself is nothing to worry about since any kernel upgrade will automatically break it.

But the blacklist, yes you'll have to manually 'undo' the custom blacklistings to be able to try the native brcmsmac or the default proprietary wl driver. If they don't work, or work poorly, they are not yet fixed and you can safely repeat... what do you guys call it... uh..

Unfortunately, I don't know of a better way to test this.