That and estimating where someone could conceivably be at a given point in time is maths so elementary you can solve it on your phone. So beams being faster is wayyyy less useful than it appears on the face of it. This honestly applies even in really soft settings because unless you can swooce through hyperspace for a brief instance (the V A S T amount of settings with FTL can't do this) you have a very easily conceived off position and trajectory throughout the engagement.

Amazing technology but it's sort of in the "running a full semiconductor chain" levels of "amazing to have, actual torture to make work WELL".

Starts with whacking the material science nerds until a good droplet size and alloy composition falls out.

Also you need to keep screeching at the computer people to give you macros that tell the system how the magnetic fields are to be adjusted depending on speed.

Ultra-relativistic projectiles end up being much more similar to lasers (except that they don't tend to spread out over distance, although they can be eroded by extremely high-energy radiation due to their high relative speed).

Yeah exactly. It's faster. But not faster in a way that matters compared to a significantly slower ship.