There will be minimal light leakage. These will be on either side of a disk, as close as I can get them.

I plan on putting black heatshrink over the LEDs as close as I can to the rotating disk.

This will be used as a way to home a stepper (fuel gauge on a flight sim); I need to find 0 easily. I'm sure there as more precise techniques, but I'm looking for a simple low-cost solution that works.

I was planning on using these steppers: https://www.amazon.ca/dp/B0CPSLS944