Timings.
Between starting the Bubbleman level (frame of gaining control) and ending the first scene (frame the screen starts scrolling vertically), the timings are:
* Baxter's movie, no special weapons: 875 frames
* Bisqwit's test, with item 2 launched in the beginning: 840 frames
* Bisqwit's test 2, with item1 trick, using item1 to avoid the frogs: 958 frames
Of course, it's not wise to use item1 to avoid the frogs. One should switch the weapons later, not there. I was just being lazy. Therefore, I made a comparison video.
* Bisqwit's test 2b, without item1 trick, using item1 to avoid the frogs: 976 frames (amazing! the lag amounts to almost two seconds of time.)
So the trick saves about 20-30 frames.
I still don't have an exact figure how much item2 saves.
All numbers are within precision of +/- 1 frames.
Edit: CoolBumpty, the idea of course is to start falling at the same frame the platform starts falling. This is accomplished by walking past it at the right edge. This prevents the platform from falling out of Rockman's reach.
When you want to jump, just face left and then hold A at the same frame Rockman gains foothold. You can throw the Item at the same frame you press left, and it will be thrown to the right.