Hi,
Your sound scheme could go in any of these categories in my opinion:

• Abstract
• Windows > Custom
• Misc

So Misc is fine by me.

Here are a few suggestions:

1. Seems like the sounds are a bit low in volume, especially compared to USB Connect / Disconnect from Windows 10 in your sound scheme. I'd suggest applying a slight volume boost. I can help if needed.
2. How about using a custom image for your sound scheme? For example, from your website:

Please note that my suggestions are optional. Let me know if you prefer to keep the sound scheme as is.

Hi, I'll check the volumes when I'm home, and the image is a good suggestion.
Do I make a new PR when I apply changes or do I somehow modify the existing file?

You can edit your file then commit again, the update will show up here.