Good question!
Beam currently doesn’t support Drum Rack choking. The way this works is, Live sends a MIDI control value 0 to CC120 to all the chains in a given choke group, besides the chain in which the note was played. Any devices on those chains need to have a “disable any active voices” on control value 0 at CC120 implemented.
The only way I can think of partly mimicking this behavior would be using a custom M4L device like this one - Choker.amxd - which enables you to map to a desired parameter (e.g. Intensity) in a Drum Rack chain and it will set it to 0. for the specified duration whenever 0 at CC120 is received:
The disadvantage of this hacky method is that you are not able to use the “choked” chain during the “choke period”.
However, we like the idea and will consider adding it in the future.