[seL4] Future plans w.r.t. Cortex-R

Dear seL4 Maintainers, Could you please share what are your future support plans w.r.t. ARM Cortex-R family - the 'reliable' and 'real-time' side of ARM portfolio? Cortex-R implementations include interesting safety features i.a. lockstep processing. It feels like a good match for seL4 safety-oriented philosophy. However, Cortex-R processors have MPU instead of MMU, which seems to be ruling them out for now. Are there any plans to have an seL4 'MPU' branch in order to support these kind of processors? Thank you in advance, Piotr Skrzypek