I discovered this oob a while ago, and shared it over here, and people told me that is wasn't optimal at the time, but since the new patch added cooling chambers to 0-4, I thought that it could be optimal to skip them with my clip. Keep in mind that if the clip were to compete with the optimal inbounds strat, the clip will also have to be executed optimally. Link to vid:

I tried finding an OOB in 0-4 on current patch, but I don't know if it's optimal. I posted it on YT, so you can see it. I don't know if it is optimal for runs on current patch, because the inbounds level is already quite optimized, but the clip allows for an ultraboost, so that compensates for the time it takes to get OOB.

Anyways, here is the video: