Hi frens. Here's a barefoot hack for you!
Confirmed working on several versions of Ryujinx, even the newest one.

> Download
anonfiles com TaZ9gdEexd

> How to...

> ...set up Cheat Engine (only need to do once)
Download and open Cheat Engine with admin privileges
At the top click "Edit" then "Settings"
On the left of the panel that opened, select "Extra" and enable "Open Process" and "Query memory region routines".
Click "Ok" at the bottom to save changes.
Close Cheat Engine
Download the cheat table from above

> ...enable cheat
- Open the downloaded cheat table and select "Yes" when prompted for privileges
- Select "No" when the popup opens asking to "Execute this Lua script"
- Open Ryujinx and load Pokemon. Fully load into the game until you have control over your character (go ahead and get the camera in view of feet so you know when the cheat is enabled)
- Towards the bottom half of Cheat Engine, click the box to the left of the text "Attach to Ryujinx". You know it worked if the text at the top-center of the window changed from "No Process Selected" to something like "0A3CB - Ryujinx.exe"
- Click the box next to the text "Pokemon Legends Arceus". You should now see a line titled "Barefoot Everywhere".
- Click on the box next to "Barefoot Everywhere". VERY IMPORTANT: This will freeze Cheat Engine for a bit of time (30 seconds or so). Just don't touch your computer (or controller) while it does it's thing. And yes, this will happen every time you enable the cheat.
- If everything worked, you should now be shoeless. Congrats.

> ...disable cheat
- Click the box next to "Barefoot Everywhere". It should instantly revert you back to having shoes.

> Issues (Still working on these)
No sound of footsteps on some surfaces
Slow to enable, sorry.