If I understand that correctly, I think that can be accomplished in Judo by viewing the combined diff of your branch by selecting its commits, or selecting one branch tip then another to see the “interdiff”. If this is something else I’d be interested to add support though.
However I found this better extension for that: https://marketplace.visualstudio.com/items?itemName=letmaik....
So I don't really need Git Lens any more, which is good because they've made it all commercial and annoying.