So far, only the stock armor & clothing replacers that came with the CBBE mod were all fine. I have been looking at a fairly large number of them during the last three weeks, and 80% of the meshes distributed with those mods had one of the two errors described in detail below. Moreover though, this was not an exception with that specific mod, but, very sadly, appears to be a rather common problem with many of the custom arrmor & clothing meshes available for FO4 so far. Upon investigation of this problem, it turned out rather quickly that the meshes were faulty.

Suddenly, the CK became extremely unstable and crashed frequently when trying to open a cell or actor preview window. This changed however recently, after installing a custom mesh replacer mod (that came with the notorious loose files). So far, the CK has working fine for me there were occasional crashes 'out of nowhere' but I couldn't say that it would crash mor often than e.g. It appears to be an accepted fact in the FO4 modding community that the CK may crash very frequently, and this may also be one of the reasons why no one seems to bother finding out why this may be the case.