In conclusion, we have demonstrated that moving from inter to intramolecularly cooperative catalysis unlocks the potential of CS2 ROCOP to selectively yield sulfur-rich copolymers. Metal choice and proximity are responsible for limiting O/S scrambling side reactions that originate from metal-alkoxide chain-ends. The strategy also achieves the copolymerisation of previously unexplored monomer combinations yielding sulfur containing polymers from oxetanes. Moving from oxygen to sulfur renders our dithiocarbonates easier to depolymerise than the carbonate analogues as the produced heterocycle is less strained. Sequence selectivity is key to enable selective depolymerisation into dithiocarbonates and to obtain semi-crystalline materials to which increased interchain van der Waals interaction upon formal sulfuration contributes. Our report opens the door for the development of new maingroup rich polymers with useful properties which were previously deemed inaccessible.