While I'm curious about your solution I need to check a few items I had on my radar already: 

1) Governance Hub - Azure Databricks | Microsoft Learn this might be what my clients (enterprises) have been looking for in Databricks (it now says it takes up to 12 hours to prepare the costs insights, so I just need to give it a little time). It's currently in Beta, however IMHO this is will reach GA relatively soon, due to the demand.

2) Then there's also GitHub - databricks-solutions/cloud-infra-costs · GitHub so I'll take a look and play with it as well

3)FinOpsWay - FinOps for Databricks | Track Databricks Costs this seems to provide an interesting view about the costs, however for corporate using such an extension wouldn't get through due to security reasons likely.

Thanks and let me see about the contribution.