I agree that the bigger the beam , the harder it is too see. But also, it would be kind of good to have this idea : the stronger the beams, the bigger they should be, to an extent, like maybe a bigger force bubble where the beams are collided at. That way if you see 2 ( or more ) beam struggles going at it, you know to stay the hell away from them when they explode lol. And the bigger they are, it also gives a better feel of power to them.
And seeing the beams grow larger as the struggle wages on would be awesome!