Ed;
I have printed Ektachrome, Kodachrome, Agfachrome and Fujichrome on Ciba/Ilford color paper and found that with an identical scene under strict laboratory control, each film required a different filter pack. Ilford's instructions even comment on this, as does the noted textbook "The Complete Guide to Cibachrome Printing" by Krause and Shull.
Each batch also has a starting pack on it which may vary.
So, based on my own lab experience under controlled conditions, and the evidence of the textbook sitting next to me.... I guess unless there has been a huge change in recent years, I would have to respectfully disagree with you.
Also, since the mid 70s, both Fuji and Kodak have supplied papers with fixed speeds so that the filter pack will not shift significantly from paper batch to paper batch. Since then, this level of control has only improved.
AAMOF, since that time, the only major bump has been with the introduction of the new Endura papers where Kodak increased overall speed and changed the ratio of R/G/B speeds. This is clearly noted on the boxes and in a stuffer in each of the earlier packages. They made this change in two incremental steps to minimize effects in the industry, but it was done for better color reproduction and faster printing speeds.
PE