I imported the obj sequence into blender or Maya (as I described above) - then exported it as an alembic and imported it into Unreal (which worked using the updated alembic importer).
As for materials: I imported the per-frame textures as a png sequence into Unreal and played it in the sequencer to match the frames of the alembic animation. The png sequence drives a material that is assigned to the alembic actor in the scene. Check out this page in the documentation: Play an Image Sequence in Unreal Engine | Unreal Engine 5.0 Documentation