The custom workspace created by the end-users using DYC and RYC do not populate in the "Workspace Canvas List" on the Expert Studio. The reason being, it is the custom workspace created by the end-users according to their preference. Only system workspaces get listed on CT Expert Studio as shown in the following screen shot. 
The SYSTEM_WORKSPACE_IND column in the CT Schema > WORKSPACE_DEFINITION table will be Y for system workspaces. However, for custom workspaces, the SYSTEM_WORKSPACE_IND column in the WORKSPACE_DEFINITION table will be N as shown in the following screen shot: 
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