Intercurent remedies

Intercurrent remedies.
There is another class of related drugs , which in addition to being needed after a certain remedy, specially allow for the repetition of the first one with much advantage. Though these may be Complementary, they perhaps require a separate healing.
A few examples
With regards to Drosera, while Hahnemann advises one single, Boenninghausen from his experience says By reason of its many alternate effects a repetition of Drosera without an Intercurrent, is seldom beneficial. (SULPHUR  and Veratrum are the most appropriate Intercurrent)
Hahnemann says of Nat mur that it can be advantageously repeated, after an intermediate remedy, if it continues to be homoeopathically indicated.
Quoting from Hale's life of Hahnemann Vol ll page 249 DR. Pierre Schmidt says Hahnemann speaks of Intercurrent remedies and says that in psoric cases it is sometimes useful and even necessary to interpolate a complementary remedy between two doses of the fundamental remedy.
The first question that comes up in our mind is how did the lists of complementries get prepared? This topic does not find a place in the Materia Medica Pura, and only stray examples are found in the. Materia Medica portion of Chronic Diseases.
Perhaps Boenninghausen had a great hand in starting this work, this being almost entirely a clinical problem, only the contribution to a common pool of observations by a number of good and careful observers could develop this branch of Materia Medica. Luckily for homoeopathy in the states DR. Constantine Hering was the central and outstanding figure, who while compiling the Guiding symptoms was in correspondence and Contact with almost all the homoeopaths in America, England Germany and other countries. Every new experience was reported and noted in the grand and studendous work. For the last fifty or sixty years that sort of combined work has been lacking and there is no one Institution or person to collect such material which from 1850 to 1890 homoeopathic journals were plentiful and voluminous. That is why we find no additions to these lists.
Are the remedies that are reported to follow well complementary or is that class reserved for only those remedies that help in some few instances only?  Secondly will a fixed or general complement  be such in all situations or conditions?
These questions I have posted for consideration by all readers. May be more than one answer to each problem.