@Mikeloeven: I just spoke to StellarFirefly. He doesn't know how to remove the glare effect.

The light has further reach.

Is this just brighter, or does it have further reach?

You do realise that the light cones themselves are not all that graphically expensive its mostly the glare effect that kills the render if you remove that youll have a much better performance

Note that HiLights are essentially just brighter spotlights. This means that they suffer from the same graphics issue as regular spotlights: They cast shadows, which can affect your graphics performance if you are already borderline. HiLights are a bit more problematic, though, because they (can) shine further and thus will cast even more shadows.

There's not much that can be done about it, except to use fewer of them if you start to experience graphics performance issues. Or to lower you graphics settings if they aren't already at the lowest.

Yay...

The original spotlights are still available. HiLights do not replace them.

Note that there is a "quirk" to spotlights in Space Engineers. They actually do not start casting light until a certain minimum distance. Even the default spotlights have this effect, but their range is so short that it is mostly unnoticeable. But once you create a mod that allows spotlights with very long ranges (like this one), it can become glaringly obvious.

Basically, if your light is set to a large radius, then objects closer than ~50% of that radius will not have the light shining upon them. (My simple workaround is to use HiLights in pairs, one I call a "headlight" and one I call a "floodlight". Set the headlight to be your long range light, e.g. radius 20, and then set the floodlight to be your short range light, e.g. radius 8.)