I've complained about this before too, but if you click the "i" with a circle around it in the bar that says "this pull request can be automatically merged" you

I've complained about this before too, but if you click the "i" with a circle around it in the bar that says "this pull request can be automatically merged" you get a nice box with all the git commands to do a local fetch and merge. I think this functionality should be less hidden away but it is there and quite useful.