As opposed to most Micronesian languages, Ulithian does not mark intranstive verbs by reduplication (but by the suffixes xa- or -xili), cf. Sohn & Bender 1973: 322.
Productivity
For progessive tense/aspect marking on verbs there is no alternative to reduplication. Rightwards reduplication is unproductive.
Sohn, Ho-min, B.W. Bender 1973. A Ulithian Grammar. Canberra: The Australian National University Department of Linguistics, Research School of Pacific Studies; (relevant pages: 44/45; 322)