I am planning to beat SMW by never running. I have made a spreadsheet that explains what I count as running and what does not count as running to make the game possible to play. https://docs.google.com/spreadsheets/d/12htPlpnJOjBETqXJfx2wHIaoJm0XewpZPprstxHM_7Q/edit?usp=sharing

Sounds Interesting! GL! 🙂
From the top of my head you could do:
y taps 3 times in bowser - you could do this while stationary and holding only up by jumping in the middle of the mecha corpse giving time before it's slowly moved out to the side of you.
y taps while stationary on yoshi to hold the key ds1 sw1 sw2 sw4
Maybe also a y tap while stationary on yoshi to bring the p-switch closer to the action might be needed idk.
dsh maybe it would be tight for time at walking speed without moving the p-switch closer, be interesting to see!
That would just leave sw3 ... maybe you could get yoshi up there with a good lakitu bounce and a wall jump or something silly?!
That's off the top of my head thoughts on how the game might be possible to play with a strict ruleset (no pressing y with any horizontal momentum or with a left/right direction pressed)... I might be missing some obvious stuff tho.. and probably more fun with being a bit less strict tho 🙂

Fitz, I have added that you can hold an item for 5 seconds if you use that item, this only applies to keys and p-switches. During Bowser you just gotta pray you are able to not die.

I did it. Got a 27:48.71

I'm probably going to redo the run but I got a strategy now. I am going to optimize Yoshi for key grabbing. And going to start the vine as soon as possible in the Donut Hills Secret House.

Yo GG! Nice strat using the corner block to bounce with yoshi dp1 I always forget you can do that on yoshi!
I strated everything out (skipped w1 assuming fine) for the stricter rule set of only pressing y/x when completely horizontally stationary and no left/right pressed (to ensure absolutely no run/fast swim state). Key's moved without yoshi by standing on them near the edge then grabing causing a spin which can move the key a marios width over, rinse repeat - as it happens in the route this is only needed dp1 have yoshi for all the others. (in water this means need yoshi since even a tap will give a frame of item swim ) and it seems totally viable.
Also verified "no run" zips 🙂 (Although rta strats would be to have yoshi )
Also, think I'm now blind after watching your next gen capture, hopefully it will pass.