It would be great if the Language (Country) en-MU is added for English in Mauritius locale.
It might be good to also add fr-MU at the same time, as French is also common.
Eike Rathke committed a patch related to this issue.
It has been pushed to "master":
add English (Mauritius) [en-MU] and French (Mauritius) [fr-MU], tdf#99372
It will be available in 5.2.0.
The patch should be included in the daily builds available at
http://dev-builds.libreoffice.org/daily/ in the next 24-48 hours. More
information about daily builds can be found at:
Affected users are encouraged to test the fix and report feedback.