Did you accidentally reinvent Extend the End pattern by yourself? 13.31 Extend the end • Johnny.Decimal
But yeah, that’s what I do. I use a bit different notation than proposed by Johnny, but using his notation this is how my index looks like:
├── 11.53 something.md
├── 11.53+KID something.md
In the file system it’s just nested directories:
├── 11.53 something/
│ ├── KID/
│ │ ├── <their files>
│ ├── <my files>
There are other approaches discussed in this forum, you can check out this topic Separate "11 Self" from Life Admin area