DN: Can the same supervisor participate in multiple Doctoral Networks applications?

Yes, they can, in case they have the capacity to mentor several doctoral candidates. They may indicate in each proposal how much time they would dedicate towards supervision, for example % of full-time equivalent per candidate, in case of any cross check between proposals. It should sum up reasonably, of course. It would also be a good practice to inform the respective consortia of the fact that they are participating in several applications, as the consortia are competing and it may be considered conflict of interest.