And I could snatch develop Brilliant Bromide with a success which no subsequent paper could match, especially no VC paper - even the best of them turn out blaah if you try. EMaks graded was a distant second option. (I'm not referring to "lith" development, but to a very subtle refined kind of control). Cd salts were still being used, and their ban probably accounted for not only the loss of Portriga Rapid, but of the rich version of Seagull G which many of us so admired. I don't know what went into the French formulation of Brilliant.
Fomatone does have decent ability for controllable snatch development - but I think it's at the opposite end of the scale from what you prefer tonally. If anyone has any characteristic curves for the Guilleminot made 'Brilliant' (likely candidates for Guilleminot's own products seem to either be Guilbrom or Prestige - the latter name having lived on with Bergger) it might tell something more of the behaviour of the paper in a more usefully comparable way. From the way Picker seems to have talked about it, the grades seem to have been specified in such a way as to prioritise highlight separation over shadow separation (thus harder grades will crush shadow values faster?).
I'm less than convinced about all the fuss about it having to be about Cd salts - the other big change I forgot to mention was the shift away from using ammonia digests/ salts - both because of much more monodisperse emulsions being made by other means & apparently because some more modern hardeners weren't compatible. Getting much more highly monodisperse emulsions (as opposed to the monodisperse-ish results of Ammonia digests) seems to have been key to getting variable contrast to work well. I do have 50's/60's, 70's and 90's Portriga here (and some blue box Seagull Portrait paper) - and could get mass spectrometry done, mainly because I want to confirm or rule out the use of Pb salts in them - that Portriga and Ektalure came to an end in short sequence, right as stronger efforts against lead use started, seems much more significant than any usage of Cd - which seems to have been used much more as a curve modifier - thus it may not have been in all grades of a particular paper. Reformulation to eliminate Cd seems to have been relatively more straightforward, eliminating Pb seems to have been a much harder/ costlier undertaking - given how essential it seems to have been to the creation of warmer tones. In much the same way, replacing Ammonia salts/ digest will have had a similarly fundamental impact on the tone of the material & the reformulation may have got tonally close, but will have changed some aspects of the material's behaviour. The shift away from ammonia seems to have been gradual between the 1970's-90's - but would likely need electron microscopy to investigate grain structure changes...
I remember reading an article where a fellow compared silver content against the black that paper could achieve. It is only one characteristic and silver content probably affects far more than that, but he found no correlation between silver content and the richness of the black. This was a few decades ago before the internet and all that.
It seems well known in the scientific literature of the industry that it's not the amount of silver that matters (unless you are reversing the film), but how well it can be sensitised, accessed & used.