ReadonlybusesPer-bus-type maxima. A count of 0 HIDES that bus type (e.g. Midas has no mix-minus).
ReadonlyinputMax input channels the appliance permits (≤ the engine's BUS_INPUT_CAP).
Optional ReadonlypathO.H.R.C.A. resource pool: when set, Σ(inputChannels + every summing bus + main) must be ≤ pathPool — the Roland "128 freely-definable audio paths" constraint. Per-type maxima still apply on top (a type can't exceed its own max even if the pool has room). DCA is a control-domain group (carries no audio, like totalAudioPaths), so it does NOT draw from the pool — it is bounded by its own per-type max alone. Unset ⇒ per-type maxima alone bound the allocation (the Midas / fixed-format model).
ReadonlystereoMay an input channel be declared stereo-width (one strip, L/R pair)?
The allocation ceiling: per-bus-type maxima, and/or a shared O.H.R.C.A. path pool.