TMX and some other panchromatic films are used to make color separation intermediates. I would expect that the individual RGB channels would be of use in their production. I cannot see a use for a visual channel off hand. What I find mising in this thread is what is necessary to make the transmission characteristics of the various filters come true. When a certain fiter of known transmission spectrum is used it is either known or assumed that the spectral response of the photocell is uniform across the photographic spectrum. IOW, the transmission spectrum of the filter is not the whole story.
I know of no photosensitive materials that are uniformly sensitive across the complete range of the films and papers we use. Unless I know that the native response of my densitometer is the same as yours, I cannot guarantee that the result I might get by measuring through a given filter will be the same you would get from your measurement of the same densities.