Plug-ins that can solve the sorting problem

[wenbopeng]

Obsidian Tidy Footnotes Adds a command in Obsidian that tidies your footnotes so they're easy to follow:

Consolidates all footnote definitions into one place, sorted by appearance Re-indexes numbered footnotes (e.g., [^1][^4][^2] becomes [^1][^2][^3])

[chrisgrieser]

The Linter Plugin has some Rules that deal with sorting. https://github.com/platers/obsidian-linter