We are working on adding VNET capability to the developer tier and it looks like this should solve your problem since you will be able to use developer tier instances for non-production environments.
For applications that require cross document join, please consider the Gremlin API: https://docs.microsoft.com/en-us/azure/cosmos-db/create-graph-dotnet, which has primitives for joins, traversals, and other graph operations.
We are evaluating expanding the SQL grammar to support graph functionality, which will provide the ability to perform cross-document JOINs. Please upvote this item to help us prioritize this work.
We plan to introduce long-lived tokens for Azure Cosmos DB accounts to address this scenario. Please email email@example.com for questions, or if you would like to learn about alternate approaches to solve this scenario.
This is a great bit of functionality that we would love to support!
Can you update your issue, or provide a comment with what language you are developing Functions in?
Thanks for the feedback!
Azure Functions TeamNathan Becker commented
We use C#, and adding snapshot debugging would help us debug our functions when hosted in Azure.
Work on this feature has started. Will update here when this becomes generally available.
Thank you for your suggestion and votes.