Please interpolate the pose of armorstands.

When the pose of an armorstand part changes, there is no interpolation to the target pose, it changes immediately.

This is not desired behaviour. Yaw and pitch changes of entities get interpolated. Position changes of entites get interpolated. Just armor stand part poses are not.

Armor stands are often used in combination with resource / data packs to display a custom item on an armorstands head. That custom item is modeled as how the entity looks. More complicated solutions do this for every part of a custom entity, allowing also custom animations.

However it does look suboptimal as armor stands do not interpolate the poses of their parts.