One thing I've wanted is the ability to group commits into a mega commit. So the history of little changes remains, but as you are scrolling you don't see all of them.
This is an interesting idea... jj has a templating language, but it's not stateful, so you couldn't like, hide some commits based on other commits, for example. But I'll file this away...
I've thought that it could be as simple as commit's with a message beginning with "minor:: " do not get shown by default.