The Void Shield is the only known barrier capable of absorbing damage for it's projecting structure, as Ion Shields merely knock incoming attacks off course. Considering ships, fightercraft, and even individual troops make use of them, a thorough understanding of their inner workings is a high priority. You are somewhat concerned about dumping energy into the Warp, as it is essentially lost to the material universe, and may contribute to the constant turmoil the Warp is in, but you do not currently have any alternative to them. Certainly not on the scale necessary to protect ships. Still, it seems like something to look into.