Transferring configuration to different themes

Problem

I am looking to change themes. Currently, the only way to copy all contexts over to a new theme is to manually recreate each and every Context and add blocks to the correct regions. If you are working with multiple sites that have multiple contexts, this just becomes pretty time-consuming.

Steps to Reproduce

1. Create a Context and add blocks using one theme.
2. Change themes, and the content for that context disappears as you are now using a different theme.
3. Re-add the same blocks on the new theme in order to see the same content that appeared on the old theme.

Proposed Resolution

When adding a block, maybe if there is a way in each block config to check off which themes you want that block displayed in, or a way to "duplicate" contexts to a different theme.