First, a note about my educational background - after high school I went off to university and stayed there until I achieved a Master of Architecture degree. A dozen years later, I went into the education field, and so had to take a whole series of additional classes in order to get certified and to advance my skill sets.
So, I've had to bend to the requirements of the APA and MLA bibliographic documentation systems. And neither makes sense to me,in terms of my own goal of providing a concise footnote & bibliographic entry that is easy for me to generate and sufficient to allow any subsequent researcher to double-check and verify my reports.
Over my 30 years of researching genealogy, the software has improved dramatically, and for those who think that complex nit-picky templated Master Sources are important, they are available. But I prefer simplicity, so I use (almost universally) the Book, Basic Format source template within RM. It lets me hit the goal stated above, but doesn't complicate my life by requiring me to learn and master dozens of different source templates.
Merging master sources based on the Free Form template into the Book, Basic Format template works perfectly, because the essential Source Details - Page Number field of Free Form exactly matches the Source Details - Page field of Book, Basic Format.
Merging Free Form sources into other templates may be troublesome (or impossible) if the fields do not match.
In my work, when I want to convert a Free Form source (with multiple citations) into a Book, Basic Format template, the process is quick and easy:
_1 - create a new Book, Basic Format source template with the 6 fields, Repository, Master Text and Media desired.
_ 2 - merge the Free Form into the Book, Basic Format source.
That's it. All done.