Take a look at version 0.30.0 - JUST RELEASED a few hours ago, yet not announced on the blog yet 
- see Metabase 0.30 RC Feedback (the whole topic from the top)
I has some improvements in this area - but there are still open issues on GitHub in this area, so this can probably evolve:
Here’s what recently got done in v0.30 - and a good starting point:
Search the GitHub issues and join the conversation and 
vote on first post in issues over there wherever relevant… if you still see important gaps