Would this be considered functional?

I am planning on using LEDs to visually clue me as to whether or not my launcher is at max power but the typical vex LEDs are hard to see if they are on at distance in a bright room so I was wondering if I got an off the market LED and used it to determine if my launcher was at max power would that be considered functional and therefore illegal since it is non-functional decoration

Most likely it would not be allowed as it is a functional aspect. A good question to ask once the new game questions opens up though.

Can you Y cable LED’s to have multiple ones light up to make it brighter?

In Vex U I think it would be legal. (just not via a laser I guess)

That sounds functional, and therefore illegal.

What you could do is put a VEX LED on the end of a 3-wire extension and place it so as to be more visible. One color of VEX LED is brighter than the others (forget which one) and should be visible from a few feet away. Or perhaps use the backlight on the LCD display as an indicator.

The red LED is brighter by a significant margin, but the LCD backlight is much brighter still and doesn’t require more wiring.