SignWriting requires some special consideration. It is a major writing system for sign languages, and to the best of my knowledge the only widespread phonemic writing system in use for sign languages. Other systems are usually logographic (with the graphemes based on glosses from the local national language), and of course sign is often transcribed in video or series of pictures (which can’t really be considered a writing system).
Its characters were added to Unicode a few years ago, but apparently the block is not enough for practical use since it doesn’t encode the proper positioning of the characters. This means that it is not currently feasible to use SignWriting written with the Sutton SignWriting block as page titles.
An option is to use @Slevinski’s Formal SignWriting standard as page titles and {{unsupportedpage}} (or similar) to convert the visible title to SignWriting.
I think there already exists a MediaWiki plugin that displays SignWriting from Formal SignWriting, similar to the one that generates Egyptian hieroglyphs. The problem would be inputting signs; having to type Formal SignWriting would make its use as impractical as that of the SLEN system. Perhaps there could be a special page with a virtual keyboard. — Ungoliant (falai) 01:41, 22 May 2020 (UTC)
What I was actually proposing as a compromise solution was a third option: SLEN would always be the default for all sign languages, but soft redirects from other transcription systems would be allowed. Can I add that option to this vote? --Numberguy6 (talk) 01:36, 25 May 2020 (UTC)
Related to option 3 ("with soft redirects allowed from other major transcription systems that are used.") and option 4 ("Use Sutton SignWriting as the default transcription system for all sign languages."):
J3133 (talk) 23:13, 22 June 2020 (UTC)
Currently, Option 2 has 2 support and 0 oppose, while option 3 has 7 support and 1 oppose. If the vote ended now, which one would we choose? Option 2 has a larger proportion, while Option 1 has a larger absolute difference. --Numberguy6 (talk) 23:02, 6 July 2020 (UTC)