Basically, I'm looking for a modular environment for routing RT and MIDI signals through different signal paths through multiple plugins, and that would occupy only a single plugin slot on any given track.

Thanks in advance!

BIAB working as a DAW plugin has been my pipedream for many years now ... F

MiniHost Demo 32/64WIN/MAC

Using Multiple VSTi Plugins on the same Track Win Mac 32 64

Biab Win More Audio & Midi Tracks

ReWire RealBand/PT

ReaStream https://www.reaper.fm/reaplugs/

Thanks Pipeline!

I had a feeling you would be quick to deliver

Try using ReaStream https://www.reaper.fm/reaplugs/ set the identifier the same for the corresponding REAPER track, put a gain control after the ReaStream vst in BB so BB makes no sound only REAPER https://www.bluecataudio.com/Products/Product_GainSuite/ or LoudMax it's lighter than Bluecat but you may need 2 to cut the volume off, then chain up the FX in REAPER:

EDIT: if you need to run multiple ASIO https://www.vb-audio.com/Voicemeeter/banana.htm

The first time you set this up would be time consuming.
But if you really need to stay in Biab:

On each BB track in the VST window Save each track FX with Save Group.
In REAPER just save it as a default BB FX project.
You can setup
Track 1 ReaStream 1 with a different set of FX
Track 2 ReaStream 1 with a different set of FX
Track 3 ReaStream 1 with a different set of FX

Track 4 ReaStream 2 with a different set of FX
Track 5 ReaStream 2 with a different set of FX
Track 6 ReaStream 2 with a different set of FX
....
....
and the same for the other Reastreams
then you just solo the track that you want to use for each track send from Biab.

So you have REAPER running each time you start Biab,
after you have the Biab song generated open the VST window
and Load Group for each track:
Track 1 Reastrem 1.tgs
Track 2 Reastrem 2.tgs
Track 3 Reastrem 3.tgs
Track 4 Reastrem 4.tgs
Track 5 Reastrem 5.tgs