Hi ariel,
Welcome to Affinity Forums,
A trial version will be available in early November.
Currently it's not possible to blend objects along a path. Power Duplicate doesn't allow this either. However those and other tools (like warp distortions, text along a path etc) are all being developed and should be integrated in Affinity Designer later. Meanwhile there's a feature roadmap available that will give you a better idea of what to expect. You can check it out here.
