I’m replacing an existing incandescent light fixture in my garage with two LED fixtures. The light is on a set of 3-way switches. I expected to remove the existing fixture and find a hot and neutral. However, the light is fed by a switched hot and tees into neutral. It was a bizarre enough setup that I pulled all the faceplates and did some investigating. If you look at the sketch, L2 is the light fixture that I plan on replacing.
O1 (outlet) and L3 are always hot, and control the garage opener and exterior spotlight, respectively. S1 has a backstab going to S2 and two wires wrapped around the gold screw. The part that concerns me is the combination of switched and always-on branches. Is this type of setup ok? I imagine it was back in the 70’s when the house was constructed, but now it seems like a ball of yarn. Thanks