I did something similar with Things and Bear, with cross-links between each. I’m using the more advanced x-callback-url Things API so that I can optionally add new tasks to the the new project all in a single call. This might be useful for your implementation. I really wanted to do the same with creating a new Files folder, but will wait until The Toolbox Pro feature comes out of beta.
https://www.icloud.com/shortcuts/e0eb81ad7db74394bbcacc4f9f60f8b7