Despite the prevalence "How to CRUSH" (punish, destroy, etc) content, there is no instant death ray for the London System, There is no shortage of videos, websites, and other content with Anti-London opening ideas.
The HangingPawns recommendations may be relevant since he is ~1980 FIDE (classical).
Recommendations from IM Levy Rozman (GothamChess):
IM Levy Rozman (GothamChess) has a video entitled Want To Crush The London System?. Some positions involve some risk on Black's kingside. The moves are designed to make London players uncomfortable. The video makes it clear some lines involve Black's f-pawn.
[StartFlipped "1"][Title "From IM Levy Rozman"][FEN ""]1. d4 d5 2. Bf4 (2. Nf3 Nc6 (2... Bf5) (2... Nf6 3. Bf4 Bg4 4. e3 e6 5. Bd3 Bd6 6. O-O Qe7 7. c3) 3. c4 Bg4) 2... c5 3. e3 (3. dxc5 Nc6 4. Nf3 f6) (3. c3 Nc6 4. Nf3 Bg4 5. e3 e6) 3... cxd4 4. exd4 Nc6 5. c3 f6 6. Nf3 g5 7. Bg3 h5 8. h4 g4 9. Nfd2 Bf5 *Why HangingPawns gave up the London System:
Stjepan Tomic (~1980 FIDE), also known as HangingPawns on YouTube, has a video explaining four setups for Black that equalize in the London and claims these led him to abandon the London as an opening for White.
I'm not playing the London in tournament chess anymore. These 4 setupsare the reason why. They allow black to equalize or even be better byforce! So against a prepared opponent, you're the one who has to fightfor an advantage in the opening. That's not good when you have thewhite pieces
The 4 Setups for Black: 4 Setups that made me Quit the London System
- Transposition to the Exchange Caro-Kann
- Fighting 2.Nf3 with Qb6
- The Boring battery draw
- The Qb6 draw
How do I play the Dutch against the London?:
GM Simon Williams (GingerGM) plays the Dutch against the London.
- Longer Chess Games #32 Climbing the 2500 mountain (slowly...) Dutch vs London System
- Longer Chess Games #62 Dutch vs London System
Other Anti-London Ideas:
- Master Class | Defeating The London System | Chess Speedrun | Grandmaster Naroditsky; See also Catching the London off Guard With QB6!!
- Beat The London System! || Learn The UltimateDefense by Agadmator (be aware)
- Beat the London System with myAnti-London byPawngrubber
- How To CRUSH The London System | ChessKid