I'm not a fan of complicated git flows, but are there really people who force push to resolve conflicts? I mean professional developers who do this on real projects?
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.