First: let me state my position:
•Beams are a bit on the underpowered side, in general, but still have uses.
•The difference in beam effectiveness against low-tech and high-tech ships does seem to be too great.
•Making them ignore shield efficiency would solve the above problem. This does have the issue of being "invisible," but shield efficiency is itself invisible so...
•Making beam weapons do hard flux and then shortening their range to prevent kiting would just make them hitscan pulse weapons with less DPS and less flux. Why would we want to do this, when ballistic and missile weapons show so much more variety than even the current energy weapons in comparison?
Beams are viable for killing unarmored targets, which are usually limited to missiles, fighters, Hounds, and Buffalo Mk.2s. They can pile a little more damage to other ships if the attacker relies on ballistics to crush shields (or if attacker is a Paragon). Being effective at point defense only and weak at any other role is a disservice to beams.
Thanks to no hard flux, beams take too much time to kill even low-tech ships.
Ignoring shield efficiency would make beams weaker against ships with worse than 1.0 efficiency.
Because beams look different and cooler (or hotter) than energy bullets, and we already have a wide variety of ballistic weapons for bullets! For killing things bigger than fighters, the only choices for energy weapons are pulse lasers and blasters (and their variants), both energy bullet (or cannonball) spitters. With some adjustments, there can be room for all energy weapons, not just non-beam weapons only. Non-PD beams are "support" weapons (or "assault" in case of Phase Beam), but are weak in those roles. Most kinetics and the heavy mauler are considered "support" weapons, yet many kinetics are good at a variety of roles.
Dissipating all the flux generated by 3-4 Plasma Cannons in time for them to reload would require 2700-3600 flux dissipation. A Paragon with 50 vents manages 1750.
EDIT: I guess you could vent between every volley. Which works great if you don't mind every enemy ship having 4 seconds to shred your hull with complete impunity between volleys, I guess.
With the Safety Override perk and vents from normal maximum to double, the latter thanks to Miniaturized Vents perk, it takes four seconds only if the flux bar is full. If the Odyssey or Paragon has no or low flux, fires three or four plasma cannons, then vents it is two seconds at most. Since the only ships that can wield multiple plasma cannons are the Odyssey and Paragon, which are capital ships, they are tough enough to take a few hits, if necessary. Meanwhile, the target eats about ten thousand damage if all shots hit. Destroyers or less will go BOOM! Cruisers and capitals will be hurt badly.
I do not install plasma cannons in all large slots without various perks and stats to back them up. I realize it takes considerable investment to support optimal use of non-beam energy weapons. However, once the player commits the resources, it is a very effective and powerful build (though not as much as the build that can win all auto-resolved battles). And, at that point, you
can use all weapon slots on a wide variety of ships for maximum DPS, then vent any flux buildup very quickly.
If it is possible to maintain pulse fire or blaster fire indefinitely, beams would be even more useless than they are now. If you can kill or at least put a dent in the enemy before you need to vent, your weapons did their job. Even hard flux alone is enough damage if the AI fails to vent while your ship retreats then vents.
Pulse lasers and blasters have short range. You will trade shots with the enemy, unless you have range perks and are fighting a non-beam high-tech ship or an ill-equipped low-tech ship. You need to deal as much damage that will stick after your ship needs to vent. Without Advanced Optics, beams may or may not outrange the enemy. If your shields ever takes enemy fire, or has dissipation so low that flux builds up while firing beams, you will need to back off to vent. While you do so, any soft flux done to enemy shields by your beams is dissipating. It is all about action economy.