I would agree. I think the 2 birds, 1 stone reference is Cooper realizing he doesn't need to reinvent the wheel to get Judy. There doesn't need to be more evil, murders, etc. and to do a lot of investigation. He can use Laura again.
But there are more 'Lauras' then ever in Twin Peaks, overdoses, suicide, drugs, etc....so that what was the exception with Laura back in 89-90 is now a norm out in the open, Jerry's legal drug business, etc.. I think one point here is that the 'happy ending' just 'smoothes this over' without ever having done the proper investigation, the negative work against the 'wrong' committed, since people were hiding from Judy, goes to then Odessa, Texas.....This is why Cooper had to destroy his own happy ending by taking Laura back to the site of the horror, to have the proper Judy/negative reaction against it, to start the investigation again, since hiding from Judy/negativity(Dougie, Old Agent Cooper), pretending everything is going to work out, or trying to possess or destroy Judy/negativity(Mr. C) both fail since Judy is 'inexistent', and this is what Cooper was so scared of, and why he had to hide in 'viva las vegas' and patronize criminals, much like life does in Odessa, Texas in the absence of Judy/negative reaction to it all.....
Judy is not mother, mother is positive life in the absence of Judy/negativity, dreams, sick vomiting because trying to smooth over negativity with simple 'factual' solutions and happy endings, which do not do justice to dreams and horror of life, thus cannot create basic conditions of community, law, dignity, etc......and these factual/mother/positive solutions(its just one bad guy, Judy, kill them, etc., everything will be great) these solutions are blown apart every day by the horror and injustice lurking right under the surface, 'sleepwalking' in Twin Peaks, rotting in Odessa in 'world of truck drivers' etc......
There are so many ideas and all of them are possibilities!
I also thought maybe the Fireman's 3 clues might simply a map to help Dale find Carrie. 430 tells him how to find the portal, Richard & Linda lets him know he's in the right place. 2 birds, 1 stone lets him know Laura is buried inside Carrie and needs to be drawn out (two personalities, one body). He follows all three, he finds Laura.
Then each clue has a red herring to throw us of in the main storyline: Andy's meeting at 4:30; Richard Horne and Linda who needs a new wheelchair; Cooper's message to Cole.
(Alternatively, 2 birds 1 stone is what prompts Dale to ask the waitress if there is a second waitress and get the address. 2 waitresses, 1 address. I agree this one is maybe not likely, but it kind of provides motivation as to why Dale asks that question, and means that the culmination of all three clues leads him to Carrie's house, which is finally marked by the #6 pole we saw in the Fireman's vision for Andy.)
Also, I'm not entirely serious here, maybe Lynch was hanging out with Freddie too long, and found it funny that a lot of English people, and I'm sure this includes Freddy, call women "birds", so he decided to make a clue about two "birds"! If Laura is a weapon like some people suggest, then it really is 2 birds/women inside 1 stone/weapon! It also fits with waitresses being birds too. Funny, but I admit probably unlikely...
Fire walk with