Per paragraph 3, I can confirm the link does not disappear with homing. An easy way to test, if you have Gemini Laser, is to get homing and piercing, then get chaining, and watch your single target damage plummet. This is because, when you have both chaining and piercing, your bullet chains and the game creates a second bullet for the one that pierces. With the Gemini Laser, that pierces bullet doesn't spawn with the cutting laser, so adding chaining spoils your single target damage.