Acoustic SMS allows clients to use a custom domain for short links in their SMS content. Here is their documentation on the subject: https://help.goacoustic.com/hc/en-us/articles/360044329913-Configure-and-analyze-shortened-links-in-SMS
We need Wikimedia to choose and procure a domain that can be used for this purpose. It should be as short as possible in order to preserve character counts in text messages. Something akin to the current link shortener domain (w.wiki) would be perfect. Perhaps one of these if Wiki owns them or can procure them:
m.wiki
s.wiki
r.wiki
Let us know if any of these are possible or if you have another suggestion we can use. Once the domain is decided, we can provide next steps to configure it.
Btw, the current link shortener doesn't work for this use case because each text message URL will have personalization includes (ex. ?recipient_id=12345).