Some apps' unprocessed streams are not muted; unable to exclude them

[BinToss]

Firefox Nightly's audio is processed, but its unprocessed stream is not muted or redirected, resulting in two audio streams.

The app is one of many that do not show in the list of packages that can be added to the exclusion list.

[BinToss]

Diablo Immortal now suffers the same issue and is not present in the "Excluded Apps -> +" list.

Previously, it was not processed at all. Now it is processed, but the unprocessed stream is not muted, resulting in two audio streams.