No, if the output exceeds the 2048 EU/t limit, the two HV transformers will divide that, or one takes the full 2048 and the other one the rest. And no, no energy is wasted in this process.
The transformer just takes the energy packet and divides it in four 512 EU packets. If it's a bit less than EV, the HV transformer takes the packet and still outputs it in HV.