This approach could be all wrong, but I think that legacy marxism is too challenged to work ‘as is’. In Last and First Men we attempted an ‘illustrated conceptual blurb’ version of an intro to the ‘net equivalent of marxism’ and that might be thought superficial. Yet the real task of the left is not so much theoretical as constructive. Theories only work in physics or related sciences like chemistry and in the social sciences the results can be counterproductive. A good example is economic theory itself.
So it is not superficial to stay away from scientism and move with a ‘praxis’ that defines tasks and procedures. Mathematical theories of economies are not binding mathematical sciences. All we can do is try and define procedures and construct constitutions and new economies to see what happens. A supply and demand curve can in fact be made mathematical but the full set of steps to a rigorous theory are elusive.
The issue is not marxism but a postcapitalist economic system and constitution: these are practical steps and we estimate their outcomes even as we estimate the capitalist calamity in motion.