There is a known issue with Particle Encoding being re-entrant; but other than that, we are unaware of other problems. If you do end up finding that there is a problem with one of our algorithms not being re-entrant safe or producing bad results, we'd welcome bug reports so that we may remedy them before the next release.
We have also thought about making a few of our algorithms take advantage of multiple cores in future releases, so keep watching ni.com/vision for upcoming release announcements.
~Nick