BusOptions

null means nowhere, and the caller wires the output itself. That is not a hole in the model: a return bus joins the mix downstream of the master filter, so parenting one to master would put every reverb tail through a filter the dry signal has already been through. The mix this replaces has always done it that way, and mixOutput.test.ts exists because getting it wrong once meant every exported clip carried the dry track and nothing wet.

Assigned rather than ramped, for the reason AudioGraphOptions.levels gives: a level that does not change for the whole of a render is not a move, it is where the parameter starts, and ramping it would open every rendered clip with a glide down from unity.