My "go to" book on brakes is the Brake Handbook by Fred Puhn. The book discusses various brake fluids. It is now published in the public domain so free and legal download.
The book is still available. Page 50 talks about "fast fill" master cylinders. I have not seen a disk brake conversion kit that uses that type of m/c. The straight bore m/c seen in Fibonachu's post is typical.