Somalis did get to madagascar, but they were part of a wave of hadrami traders
not colonialists.
There are legends of a somali saint bringing islam to the Maldives,
but the question is what would you consider a Somali?
Since allot of these people belonged to arab tribes that assimilated into the Somali clan structure.
Ajuran was a Somali state, but Adal came to be dominated by Somalis during the later periods the Somalis had the same role as the turks did in the Abbaasid state, primarily as soldiers but then came to dominated the non somali ruling family.