I have the exact same issue but I never knew there was targeted weight training for the VMO beyond “focus on it harder”. Could you list what you did?

As far as lifting goes, many cycling coaches will recommend extremely high volumes of lifting because cycling is an endurance/aerobic sport. In my opinion this is fallacious because that fatigue/energy/time is best spent on riding, not lifting. In order to maximize your benefits from lifting weights and your enjoyment of riding, I would stick to low volume, high load (3x3, 3x5 or 5x5), free weight lifting. Avoid the leg press, smith machine, hamstring curls etc. if you want to get the most out of your lifting. Deadlift, squat (just below parallel, not the half-squats many cyclists do), row, bench, pull-up and overhead press. Maybe some isolated ab exercises if you’re worried about injury.

The reason I recommend 3x3 or 5x5 and not the conventional 5x8 or 5x12 or 5x50 that many cyclists do is because the biggest benefit of lifting weights is not training the endurance of your muscles. It’s convincing your brain that it can send signals to your muscles to fire much, much harder than it realizes. It also reinforces your muscular/skeletal system structurally, which is important for your brain to develop confidence in your body.

What you’ll notice is that, as your 1RM gets really high (say you can deadlift close to 2x your body weight), doing easier things like riding will fatigue you much more slowly. As an example, I can climb out of the saddle for 10-20 minutes straight, nearly. My buddy who has about the same amount of aerobic endurance as I do can’t really stand for more than a few seconds before lactic acid starts pooling up. We weigh similar amounts. And of course, you will develop a monstrous sprint, as long as your technique is stable enough to harness all that torque at high rpms.