Custom filters spread like viruses
ParaView seems to append all custom filters to any statefile that is saved (even custom filters that are used), and further stores any custom filter, that is read from a statefile, in the local config.
Full writeup, with .pvsm, is here: https://discourse.paraview.org/t/custom-filters-spread-like-viruses/2597
OK to slip to 5.9.