Is it within regs and feasible to take a 32A supply from a Cooker control unit to feed into a 16A FCU and feed out again to supply 2no 32A DSS's?
No such thing as a 16amp FCU. If you want to feed two sockets, you could.....as long as you no longer wished to have a cooker connected. The cooker panel would therefor no longer be required. Sounds like you are having some kitchen work done by your two posts, and are trying to trim at the edges What needs doing, no doubt needs doing. Don't second guess your spark!