Actually, looking into the source, it seems VulkanRHI has raytracing support in the ue5-main branch- perhaps it’s possible (or even practical) to backport the changes to the Engine/Source/Runtime/VulkanRHI to 4.27? See git diff --stat origin/release origin/ue5-main -- Engine/Source/Runtime/VulkanRHI/ to see direct changes- but related changes to code outside of that directory may prove more interesting/complicated.
Any commentary from someone more familiar with engine code (maybe an official dev?) would be appreciated on this front.