"This converts radv_CmdBuildAccelerationStructuresKHR to a simple shim that pushes the actual build commands to a queue, where they are accumulated and dispatched as late as possible.
This helps especially with games that don't do any build command batching of their own. For example, it triples the performance of Hitman 3."
This is Vulkan. Cycles uses HIP to render. The 3x boost is in a single game. As the quote says, the boost is from batching commands to build the BVH, which even if Cycles did use Vulkan (very unrealistic), BVH building is not the majority of time most people wait for with Cycles, and even if it were, I have to wonder if batching would even make enough of a difference for Cycles, or isn’t already implemented where it makes sense for it to be.