Look at Reajs VST it allows you to use all the Reaper audio midi Plugins in any other VST Host. It also has a scripting editing within it.
It has a audio and midi In, audio and midi Out.
It will only load in Biab as and audio FX so Biab won't give it midi In, and because it loads as an FX Biab won't send midi Out.
https://www.reaper.fm/reaplugs/

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