Reposting from the discord. This is somewhat hand-in-hand with my comment about the WR being too dismissive of its own quality.

If you get 11 coins out of both coin blocks, you ultimately have to choose whether to get the 50th coin on the first life (after exiting the pipe), the second life (the third block where the two goombas are), or the third life (same).

It is possible to save a frame rule on WR getting the coin on the second life. Times are off a bit because I'm recording at 60 and not 59.94.
• Exit the pipe such that the blue sky appears at 14.366 or earlier (alternatively, the time should appear at 15.983) or earlier.
• Run straight into the goomba and die at 17.066 or earlier
• Start second life at 23.066
• Execute WR pacing through the 10-coin block, getting the 11th coin at 29.716
• Run right and get to the second of three coin blocks at 31.450
• Jump and get third coin block at 31.816
• Die to the goomba without stomping it at 32.000 (frame rule is at 32.066 so there's 4 frames of leeway)
• Start 3rd life at 38.083
• Repeat that execution on the 3rd life, as far as the 2nd coin block, and get 46.450

It is also possible to exit the pipe fast enough on the first life to get the coin, die to the Goomba and still catch the early frame rule (14.183 blue sky, 15.800 timer appears). This would add more leeway on the second life to catch the 32.066 framerule, but wouldn't be enough to save us another frame rule overall.

So you either need a ridiculously fast first life, or a ridiculously fast second life - your choice. And in either case you need to snag a coin and fall into a Goomba without stomping it, which I still find tricky.

Getting the coin on the third life is easier because you don't have to mess with the goomba stomping, and it's easier to catch the above framerules because you're doing less on the first two lives. But then you have to spend extra time on the third life, and you can't catch an EARLIER framerule. So this route is just going to be slower. Based on the WR and my own PBs, 46.816 is going to be close to what you can get this way.

Also note that the time from second to third block on life 3 is longer than the difference between dying to a goomba and getting a coin on the other lives, since it takes a few frames to get from the coin to the goomba in either case anyway, and on the 3rd life you end immediately at 50 coins.