Are WorkspaceConfigProperties Available in BUI Extensions?

Summary

AddIns can use WorkspaceConfigProperties to control their behavior with a workspace-by-workspace granularity. Is the same or a similar feature available for BUI extensions?

Content

Please see the attached image for examples of WorkspaceConfigProperties in code (feel free to ignore the red squiggles - I don't care about those) and in the .NET console's workspace editor. I've looked through the documentation and scoured the discussion forums, but I haven't found a way to do this same thing within a BUI extension. I can recreate this capability with a custom object/report/workspace if necessary, but I'd much prefer not to re-invent the wheel.