Hi, another linguist here!
In Finnish it is common to have a /VVV/ constraint.
'kauan', 'huoahtaa', 'aion', etc.
Both /iu/ and /ua/ are also diphthongs in Finnish.
Kiuas is pronounced /'kiuas/ (IPA),
which would be (for English speaking persons)
key-was, where 'key' is short, and...