As for the Spire Beam, if it stops at the first target it fails to kill, how is it different than the HBC beams?
A lance is always only 1 beam, not a fan, and it actually fires once per frame for 2 seconds (damage divided amongst the frames) rather than just once on the first frame.
Ok, back to this. I attempted to get a precise duplication of what I'd seen, and I've managed to do so - sort of. It looks like the consistant problem I've seen is with the Shadowblade's beam weapon. The starbase's beam weapons seem to behave as they should.
I've attached a save file where you can see the Shadowblade's beam about to hit, then not extend when it is no longer hitting something. This means 99% of the damage it should deal is being wasted. Load up the save file "Bug Report - Shadowblade beam about to be cut short", pause, the switch to Player 1's Champion (ctrl-H) in the nebula, and watch.
I've also noticed an issue where sometimes the weapons will penetrate one forcefield to hit a target inside. I've attached a save for that, as well, "Bug Report - Shadowblade beam about penetrate forcefield".
During that same scenario, something strange happened: Some of my allied ships started to leave the nebula before the scenario was over! See the save "Bug Report - Nebula Allies leaving nebula before scenario is over" for that.
Finally, I grabbed some Spire Frigates, and messed with them. What I saw there was that sometimes the beam would not extend for a little while after killing or moving off of its target; or more commonly the beam would simply pass over a target without damaging it. I've attached a save "Bug Report - Spire beam missing targets in path" where you can see this. Pause and switch to the Fallia system (right next to the Homeworld) to see this. It's a lot more obvious if time is slowed down (-5 or -10 makes it REALLY obvious).
The Spire Beam description "Fires a coherent beam of light for two seconds that strikes all enemy units in its path." seems to describe it as a buffed version of the ZBeam's weapon...
It means "all enemy units in its way"; I can change the description to that if it helps.
I don't know what phrasing you could use - neither the HBC nor the Spire Capital Ships themselves actually describe the beam the way the ZBeam frigate and the Phonton Lance module do. Maybe something like "The photon lance deals damage to the first ship it hits, continuing on to deliver its remaining power to any other ship in its path if the first should be destroyed" might make it clearer. I think I probably got confused from a post here on the forum where I misinterpreted something that was said, rather than from the game's text itself.