Kosmic gets two 1-ups in 1-1 in this run: https://www.speedrun.com/smbce/run/pydooo0z

It seems that Second Quest can indeed be used, see https://www.speedrun.com/smbce/thread/1tnk1/1#mgxds "Level select / second quest is allowed in categories that do not beat the game ..." But: "All categories begin in first quest, except for "Second Quest" and "Second Quest Warpless ..." So you would have to get to Second Quest first and the time for that (at least 2:40 min if you do Minus World Ending) would be added to your run time.

Congrats on your 2:34!

Here are the visual cues I'm using:

1. Try to line up the top of Mario's sprite with the top of the left cloud before the stairs: https://imgur.com/93ujuKe Swim on that frame (press and hold(!) A).

2. Do another swim when Mario is in the middle of the other cloud, i.e. quickly release, repress and hold A. Mario's head should be barely above the cloud, see here: https://imgur.com/LP9tywE

3. Perform a third swim when Mario is above the koopa: https://imgur.com/i0op3IE Hold A until Mario starts to move downwards.

This should set you up correctly for the Full FPG. Mario's vertical position doesn't need to be exactly like in the pictures, and there is quite some leeway for the three A presses. Here's a video of me using this setup in a run:

You might want to hold D+R when you touch the ground right before the flagpole. It makes it less likely to get fireworks. For some reason, I get the Full FPG less often when I press D+R, though. Hence, I don't press any direction on the D-pad. But with the setup described above, I'm getting fireworks much less often as I used to anyway.

Good luck!

@KilleDragon That definitely saves the framerule. I saved it in the video.

(1) I don't really understand the details of the glitch, but I guess it's something like this: When you climb a vine, the next screen (e.g. the coin heaven in 5-1) starts with an animation of the vine growing and Mario climbing it. So when Mario is still on the previous screen, the game probably sets a flag to remember that the next screen has to begin with this animation. But if Mario dies on the vine, he never reaches the coin heaven. But since the flag is still set, the vine grows on the next screen, which in that case is 1-1.

(2) When 1-1 starts, Luigi immediately grabs the left part of the vine. If you hold right, Luigi will get to the right part of the vine on the next frame. This teleports him quite a few pixels to the right. You can see that if you watch the youtube video frame by frame with "." and ",".

Interestingly enough, there is a difference between Mario and Luigi. It is actually possible to get a 4:53 (with L+R) when playing as Luigi by using the vine glitch. Here is a TAS that shows how to do it:

This video shows the inputs for 1-2G:

C40 is when you go for D70, but press B a frame late. You can find the inputs for 1-2 FPG in the original thread (see link in my previous post).

There is a setup for 1-2 FPG that I found a couple of month ago: https://www.speedrun.com/smb1/thread/tfeq1

The inputs are only slightly different compared to 1-1 FPG: You have to land on the 2nd pixel of the step (instead of the 1st). Then you do C40 inputs (instead of D70).

The last sentence means that you do the inputs that would give you C40 in 1-1 (when landing on the 1st pixel). They actually give you D70 in 1-2.

The inputs at the flagpole are the same.

I think it's more difficult than saving the 8-1 FPG framerule. Saving frames in -3 to beat the current WR is definitely much easier than going for the -2 clip. Hence, I don't expect anyone to go for this in runs anytime soon. The time of the TAS I present in the video is 2:30.935, exactly 3 framerules faster than the current WR. So yes, 2:30 is possible, but extremely unlikely to happen.

I found a (barely RTA-viable) setup for the clip in -2. It saves 3 framerules over the normal FPG and is only 1 framerule slower than HappyLee's TAS.

I made a video in which I explain how to retime runs in the category "10 Lives". It's not very intuitive how the game behaves during the infinite 1-up trick, so it took me some time to understand what's going on. The reason I looked into this is because Roy's WR has been retimed incorrectly. Following the way to retime runs that I propose in the video, the WR should be a 1:28.504. My current PB (not yet verified) should be 3 frames slower (1:28.554, I retimed it in a different/wrong way when I submitted it).

You can find the frame rates here: https://www.speedrun.com/smb1/guide/v5oa1

I compared the frames on which the screen turn blue (frame number 2109 vs. frame number 1964). Also, the 400 under "TIME" in 1-2 appears exactly 145 frames later.

I just tested it again on BizHawk, the difference is 145 frames. I don't know what causes it to be not a multiple of 21 then.

Some time ago I noticed that if you don't take the pipe in 1-1 you will enter 1-2 exactly 145 frames later (compared to taking the pipe). But 145 is not divisible by 21. So my guess is that the framerule timer is also paused during pipe transitions.

I didn't know that there can be a flag in -1, but I've verified it on original hardware (FDS). I guess that you have to kill the koopa on the stairs. It also seems to help if you scroll the screen to the right and move pixel by pixel like I do here: Sometimes there is a cheep-cheep at the bottom of the screen which seems to prevent the flag from spawning:

In short: Time starts when the 400 appears (at 1:49.100 in your video) and ends when the axe disappears (at 4:28.533). The time difference is 2:39.433.

I just looked at your run. The time I got from the video is 2:39.433. The nearest possible times considering the NES frame rate are 2:39.421 and 2:39.437, so the new time seems fine to me. I guess that the 2:39.504 was a mistake that was corrected later.

I don't think he's talking about Mario walking to the castle, but the cut scene afterwards, where Mario walks towards the pipe (the one before each underground and water level).