In this recent SC Court of Appeals case, a defendant was tried twice for burglary. In the first trial, witness A testified. At the subsequent trial, the defense attempted to locate and procure the witness, however they were unable to. The defense sought to introduce witness A's former testimony. The state did not object, but they also pointed out that right before trial they were able to make contact with witness A and the witness claimed that they were never served a subpoena. Before the court allowed the former testimony to be read in, the state objected to all of it coming in. Rather, they just wanted portions of it to be read. The defense objected to the limited admission of the testimony. But the trial court let in only portions.
The court of appeals didn't directly address the issue of limiting former testimony under 804(b), but rather held that the testimony should not have come in at all under 804(a) (the declarant wasn't unavailable, "process or other means").