But as Delenda Est showed, beam jamming is something that the GTVA can counteract pretty much out of existing resources. Widespread deployment of the technology (which is something that isn't trivial, given the scarcity of Oculus hulls) will help to make the Tev's alpha strike advantage less acute, but it's not going to be nullified completely.
Delenda Est showed the ultramodern, highly experimental GTD
Carthage can blow up an Oculus after a fighter's TAGged it. Even that isn't guaranteed to work, since the BP discussion thread has described beam jamming as a combination of ECM to throw off targeting and EM disruption of the beam's magnetic bottle; this hasn't been confirmed, but I suspect the
Carthage's ability to lock the
Hanuman is a combination of the TAG missile and the distance between the two more than some flaw of the jamming tech itself.
Oculus spaceframes may be rare, but the Jovians built at least "several" prototypes "[i
]n the weeks leading up to the Fall of Jupiter", according to the tech entry. (I had actually been under the impression that they'd been available to assist Calder's forces in the 18 months before WiH; that Calder was able to maintain a stalemate even against full-strength Tev alpha strikes suggests that either they're not usually as deadly as proposed earlier, or that Severanti egregiously underutilized them. I suspect some combination of both, leaning towards the latter.) Now, the rest of the UEF probably doesn't have too many flux tube probes laying around, but if some Jovian engineers can "jury-rig" a fully capable ECM ship in a few weeks, I doubt the UEF would have trouble adapting the design to a more typical hull configuration... well, unless a certain metal-themed admiral decides to smash their logistics out of nowhere.
@Snarks: Simms mentions UEF shipyard output as a going consideration in the briefing (or maybe the CB, I'm not sure) to
Pawns on a Board of Bone. That doesn't mean the fleet is growing, but I think you're underestimating somewhat. I don't think canon mentions any new warships coming online post-Severanti, but that doesn't mean it isn't happening. Further, we only have that perspective post-Steele. Severanti both inflicted fewer casualties and didn't prioritize attacking their economy, especially in and around Earth sector where most of their shipyards seem to have been located.