I'd like to put you a glue, (at least for me if I have one).
I am a woodworking student and I work on solidworks. I had a question about using the function library.
I want to create "function models" that will be operational in the part and also in the assembly and then automatically reflect them in my parts. My goal is to standardize some of the machining I do at school. And then, integrate additional components in order to receive everything in my nomenclature.
I first tried the function library which is not functional in the assembly. I tried to use the smart components, but I find myself with too many problems for symmetries. The principle does not interest me. I tried macros, but the principle doesn't suit me for reference reasons.
Anyway, I noticed that on the topsolid software, we can create any "function model".
I think part of my problem is in the Swood add-in, only I can't afford to work on this software.
There you have it, I hope I have been clear enough.
If smart components don't suit you, the best is the library function (I don't use smart component functions, but I don't understand the problem generated by symmetries).
To say that library functions don't work in an assembly is a false problem for me. You just have to review your work methodology according to the constraints of SW (a classic to avoid bugs under this wonderful software...). The design of the functions is also very important (the number of external references to be limited as much as possible if you want something robust): you can quite easily create functions that are unusable in practice.
In terms of methodology: an alternative to assembly can be the multibody part: this might be more suitable in your case since it doesn't seem that you detail each part (external references create risks of error for parts with their own drawing). The construction tree can quickly be very complicated on the other hand so you have to give yourself rules for naming functions if you want to be able to work efficiently with this kind of very complicated part.
For the functions of Libraries, you can draw inspiration from the work of "Pierre Granouillet" on his website: http://bib.altitech.free.fr/ver_2-2.html It's a bit old-fashioned but still effective.... A few screenshots would help us identify your needs more clearly... As for the "smart" components, I don't recommend them... especially if you have to duplicate your Assemblies...