Nothing wrong with doing that on a feature branch after rebasing, as long as you are sure no-one else has pushed any changes to that branch in the meantime. Although personally i prefer --force-with-lease, which will warn you if that's happened.
If anybody pulled in the meantime and they don't know you are forced pushing they also might get in trouble because of your force push.
If you have conflicts on a feature branch I guess you aren't the only one working on it and as soon as that's the case force pushing is generally a bad idea unless you coordinate carefully with the test of the team.
The only time I ever force push is on a feature branch that only I work on and I want to amend the commit I just pushed a second ago.
