Honestly, no one knows. The man is impulsive and short-sighted. The only things are definitive about him are his thirst for war and unwillingness to listen to good counsel.
But in general, Ethiopian administrations and elites prefer Asseb Port. It is closer, historically 'theirs' and is populated by Afars, a more friendly group than less reckless and unpredictable Somalis.
The rumor is he wants to start the war sometime in the fall when the US is busy with elections much like he did with Tigray war which started November, 2020.