The only problem with Warp clipping at 4-2, is that you'll lose the mushroom earlier in the run, but by doing just the Fast Vine is enough to save some time at 4-2. Feel free to ask anything if you need/want.

The only trick I got was the 1-1 clip. Got pushed out many times and am not consistent enough to do it in runs.

that fast vine is awesome. good find!

Nice! I'll have to try these out!