[oggy]

The idea is not to replace every banking system, but to create a network with a sufficient technological edge over existing solution and sufficient business value.

CHESS is definitely a complex beast. The go-live date has moved from 2021 to 2023, AFAIK at the request of the participants. To your question when it will be directly (as in, through DAML) used by all participants - I guess at the point where it generates enough value that it's advantageous for them to use it.