I’m a fan of Proxy but TS supporting dynamic props aren’t so clear for me.
Can I somehow tell TS that a class implements an interface in a dynamic way like that?:

Playground

class MyElement<T extends HTMLElement> implements T{
    static create<T extends HTMLElement>(elem: T){
        return new MyElement(elem);
    }
    constructor(elem: T){
        return new Proxy(elem, {
            get(target, prop){
                return target[prop as keyof T];
            }
        });
    }
}

const body = MyElement.create<HTMLBodyElement>(document.body as HTMLBodyElement);
console.log(body.innerHTML);