I understand your logic here, and for the Kortul it would look fine (though would make it far weaker because its pulse beams would be just barely above 12.5 DPS), but for the Radiance which has two parallel beams, it would look weird as you have to face your opponent to fire them. The same applies to the linked beams on the Kol. The beams focus on one single target and each one does about 4 DPS at level 1 and only about 12 at level 10... They are best together. If you link the top two and the bottom two, you just made it weaker... Sure, it won't affect mitigation, but it only barely does anyways.
If you made each cannon individual and split into two beams, I would change the code myself to undo what you just did. The Kol is suffering as it is with the nerf of SC's. If you made beams split, you would kill the thing. Sure it still has health, but so what? If you can't do anything, it is only good against soaking damage from illums.
As far as making it toggleable, don't do it! Sure it would add some "strategy" or "customization" to the game or "would allow for better microing" but frankly, I don't care. I micro constantly and this would do very little if anything. As is, the linked beams barely scratch anything. They are at the 12.5 mitigation break. They are best as they are.
Yes I read your second paragraph, but it still applies. You don't want to split the weak damage of a weak [offensive] ship. It doesn't work that way. I understand that you want to make caps better, but this is not the way to do it. The rear autocannon on the Kol is good as it is. Sure, the effect of seeing all those laser and autocannons firing would be awesome, but the reduced damage would do more harm than good... For this reason, I do not like the idea.
(for the record, i am done venting...)
If they seem weak at high levels, go to the thread about making them researchable... That includes ideas for buffing existing ones and creating new weaker ones to fill the gaps.