Are there any templates or useful packages for writing a patent specification, such as the ones in this collection?
I know about these two. The first one looks good and was successful used by the author for his patent applications. The other one is quite old: it is packed as shell archive and for LaTeX2.09, but works well with a modern LaTeX2e. I can't tell you more about them. All my patent applications had to be written in MS Word.
http://dodge.stanford.edu/~echmelar/inventions.html (look for "
I found this LaTeX template online on this link:
Starting from 2023: DOCX required
Filing a new non provisional 111(a) application? Starting January 1, 2023, specification, claims and abstracts not filed in DOCX format will incur a non-DOCX surcharge of up to $400 for this filing type.
See USPTO: File patent application documents in DOCX
If you hate M$ Word as much as I do, writing the application in Markdown using the Vim text editor and converting it to DOCX using Pandoc and the provided USPTO DOCX template, might be a very viable option.