That really doesn't sound right. Beams aren't any much more efficient than normal weapons (or at all in some cases), and the range with HSA is truly terrible. If going low vents with lowish efficiency, that just sounds like low damage output combined with low range, which is not good.
Instead of an HSA ion beam, why not just an ion cannon? Way less flux (100), same damage, almost as much range (500 vs 600), way fewer OP (6+ HSA marginal cost), small slot instead of medium. And the phase lance is only going to have 400(!!!) base range. At that point and AM Blaster is competitive in the slot, though I suppose an HSA phase lance is better than an AM Blaster except for range, unlike with the ion beam. HSA + AO for 500 range? But that's a lot of OP for replacement AM Blasters!
Gravitons are efficient, but without their range they are just worse than something like a single light autocannon.
Yeah, you're not really factoring in the shield arcs. Those will not only reduce return fire, but they have a fantastic tendency of killing engines once you've got the target at higher flux. Rooky mistake.
I never said the phase lance and ion beam were for building flux, I said they were relatively efficient. You really would need other weapons for building flux. The two I recommended were for locking in a kill.
The increased flux cost doesn't quite matter if your base dissipation eats it entirely, and as I said, the build as a whole will be underpowered, likely exceeding weapon flux by a fair margin. The shield efficiency is the build.
I'd recommend it on a Fury, actually. HSA phase lance wolves are an option, since they're never going to really overpower anything because of their weak dissipation. So you build them for as much cap as you can to make sure they survive poking. Also, free tip : none of the frigates with hard mounts are fast enough to track other frigates in a fight! Auxilliary Thrusters are a must!
I've had success with something like it on an Odyssey, but the primary force was [ultra redacted] weapons. So not very applicable. Nothing could pin it down, and it had fairly strong shields with such a low weapon cost, it just bled off flux at any convenient moment. Very nice.
That said, I wouldn't use HSA on the Odyssey. That shield arc is too wide and the armor is too fragile. Cruisers are the size limit.