I fixed an issue of my utility for polygon width calculation in a given direction caused by redundant geometry created in certain circumstances. 'Fixed' - somewhat a too strong claim for a nasty about 100 lines long workaround-function, where I had to comment almost every line to trace what is going on (optimisation is left for the feature). Nevertheless full functionality of the utility is now available! Updated version is here.
Another note: check validity of your polygons geometries beforehand to obtain correct results.