Hey, sorry for the late response.I've done a run under 20s with the 5-7-nerf and the time is still improvable. Furthermore I agree, that it's impossible to beat the best time under the current patch.

However if you are still into running Gun Range under the current patch you can check out my run under the 128-tick section. It also displays a consistent way to do the 3k-nade, which should also work under 64-tick. The hitreg issue is pure luck tho :)