An embolic material delivery device in accordance with at least some embodiments of the present technology achieves a high pressure rating with a small wall thickness. The device includes an elongate conduit body configured to extend intravascularly toward a treatment location including an aneurysm. The conduit body defines an axial lumen through which viscous embolic material is conveyed toward the aneurysm while at least a portion of the liquid embolic material is at very high pressure (e.g., 9,000 psi or greater). The conduit body includes a metal hypotube coaxially disposed around the axial lumen. The hypotube includes cuts configured to increase a flexibility of the conduit body and bridges between the cuts. The conduit body further includes an elastomeric jacket extending around at least a portion of the hypotube. An average wall thickness of the conduit body is within a range of 0.005 to 0.007 inches.