How dangerous is 'sudo hdiutil eject -force /Volumes/path' for filesystem integrity in terms of cache flushing and open file integrity?

I find myself having some trouble sometimes with ejecting volumes normally. Usually this seems to happen with volumes that really don't (or shouldn't) have any files open that are non-negotiably being accessed or used. For example, these are usually volumes that have neither any open documents nor any files that should be being accessed by anything other than Time Machine or Spotlight. Usually a sudo hdiutil eject -force /Volumes/path will resolve the issue, but I've recently had a friend raise a concern about whether or not a -force ejection might not flush any caches and perhaps not finalize writing data to the disk when given the -force directive. Is there any definitive information or testing in this regard so we can know with certainty what occurs here when -force is used with eject?