Algorithms for logical synthesis of multiple output bits?
as you realize, while universal, Quine-Mcclusky is only a "bitwise" construction method (single bit output) that does not recognize/ exploit common subpatterns for multibit outputs. multibit function construction optimization is a very broad area handled by EE type papers/ applications/ algorithms, there are very many published. the general topic is "logic synthesis". there is also a very broad array of software built for this purpose both commercial and public domain. here is an example of a relatively recent survey of algorithms and also a technique of using known/ previously computed circuits in a library-like context. this paper is useful here in that it refs many of the top systems in use and gives a consolodated view that you seem to be asking for in particular.


Lazy Man’s Logic Synthesis / Yang, Wang, Mishchenko