Should --update-refs exclude refs pointing to the current HEAD?

The --update-refs option of git rebase is so useful that I have it on by default in my config. For stacked branches I find it hard to think of scenarios where I wouldn't want it.

However, there are cases for non-stacked branches (i.e. other branches pointing at the current HEAD) where updating them is undesirable. In fact, pretty much always, for me. Two examples, both very similar:

1. I have a topic branch which is based off of master; I want to make a
copy of that branch and rebase it onto devel, just to try if that would
work. I don't want the original branch to be moved along in this case.

2. I have a topic branch, and I want to make a copy of it to make some
heavy history rewriting experiments. Again, my interactive rebases would
always rebase both branches in the same way, not what I want. In this
case I could work around it by doing the experiments on the original
branch, creating a tag beforehand that I could reset back to if the
experiments fail. But maybe I do want to keep both branches around for a
while for some reason.

Both of these cases could be fixed by --update-refs not touching any refs that point to the current HEAD. I'm having a hard time coming up with cases where you would ever want those to be updated, in fact.

Any opinions?

-Stefan