[seL4] Are there any plans to re-add seL4_Untyped_RetypeAtOffset?

Speaking of things that would be useful for large dynamic systems, are there any plans to add seL4_Untyped_RetypeAtOffset from the old experimental branch to the current mainline kernel? I am writing a buddy untyped allocator for UX/RT, and being able to retype at arbitrary offsets would reduce overhead quite a bit because I could just retype from the highest-order untyped objects most of the time rather than having to create two child untyped objects per split. If not, I will probably end up re-adding it myself later on (sometime after UX/RT is running actual user programs).