Each year I say...one more year... The plan was always to have a wide flattish top and short low branches (as per below) - that's why it's a bit ''top heavy''
You'll have to forgive me, I am a naturalistic person rather than Japanese teaching. Your virtual silhouette has Juniper pom poms. But its an Elm.
I think they should look more wild, less tame but obviously bonsai requires some sort of taming.. so a balance.