You Probably Care Too Much About Exercise Form
“Proper” form is not the end-all be-all when it comes to injury prevention nor being able to lift more weight. There are many high level strength athletes who have unique forms when lifting and are healthy and injury free.
Muscle Activation Is More Dependent On Load Than Form
It's commonly believed that small tweaks to your exercise form can sometimes have huge results in terms of muscle activation, and you can use this to preferentially target certain muscles. However, it's far more important to focus on good progression first.