Having similar problems. It works sometimes and sometimes not. Not sure what is triggering the issue exactly, but I find that frequently when certain audio plays from an application (like my email application, Canary) that it will stop the audio and then I have to completely quit Bongiovi DPS, then manually switch to Line Out and then start Bongiovi DPS back up. Bongiovi DPS then grabs audio again and things sound nice once again.
I’ve also found that Staticz’s Sound Control has problems with Bongiovi DPS as well. Apparently one of the problems is that Bongiovi DPS reports to the OS that it has volume controls, even though it’s ignoring them. Sound Control’s developer is trying to deal with this problem in the way Bongiovi DPS works (hopefully the Bongiovi DPS developer will change it so that this is handled properly), and is going to have a fix out soon for this errant behavior, yet I fear that there are other things going on here as well.
Generally yes, there are some problems with Bongiovi DPS in High Sierra.