I have a build process which tags successful builds (which is nice). I like to sync the tags so that I can find them using the left-hand column in SourceTree (under "Tags"). However, when viewing the log for a given branch (using Git, but I'm guessing the same would be for Mercurial), then the tags take up the full width in the Description field (See attached screenshot).

I would suggest placing the tags (and the HEADs and all the other "tag-like" values) in a separate column - that can be reordered and/or hidden as needed.