After the recent months worth of various people's commits becoming sub-revisions of one person's commits, I chatted on #bzr to see if there was a way to avoid this.
Incidentally, the branch based workflow shown on the wiki will *cause* this problem, so I'll revise what's written there.
Anyway, there is a bzr configuration flag which will prevent changes (other than extensions) to the log, i.e. it would refuse to accept the push which sidelines other people's commits.
According to the #bzr people, this would set the flag on lp:inkscape
python -c 'import bzrlib.branch as b; b.Branch.open("bzr+ssh://bazaar.launchpad.net/path/to/branch").set_append_revisions_only(True)'
(if the user has the required permissions)
They also pointed out the current sidelining could be undone, I might see that's involved, but not really sure if it's worth it, seeing there's no real damage.
Cheers -Terry