" Grundprinzipien kommunistischer Produktion und Verteilung" is a very good read. They are critical of Leninism, but from a thoroughly Marxist POV. One of their key concepts is replacing money by time accounts, solving the problem Mises pointed out that a planned economy still needs a unit of measurement. But unlike using the very imperfect valueform of capitalism it uses the objective measurement of how much time is contained within a product.

There is nothing in the GIKs work that is an endorsement of Gobatchow though, the tweet is complete nonsense.