The SRND says there is no resiliance with CUCMBE 5k or 6k as follows:
Because the Unified CMBE BE 5000 or BE 6000 resides on a single standalone platform (a combined publisher and single subscriber instance with no ability to configure a secondary subscriber instance), it does not support node clustering and therefore it cannot leverage the call processing redundancy schemes available with Unified CM. For this reason, call processing and registration redundancy for endpoints in these types of deployments can be provided only by SRST or Unified CME acting as SRST.
The ordering guides for CUCMBE say you can order a second UCS-C200M-VCD2 server for full resiliance with CUCMBE 6k with an example on page 26
If resilance can be deployed is this just for CUCMBE or does it include Unity CX (the guide states to order Unity Cx HA) and then what about CUPs and UCCX?