I am having trouble getting two surfaces to blend smoothly. The render reveals how this connection is abrupt and does not transition well. I have corrected the tangencies of the curve ends but the area in-between are still not as smooth as I would like (see rendering).
looks like the tip you build is a 90 degree revolve surface.
both surface edges of the tip therefore are rectangular to World XZ or World YZ plane.
your cone-like shape isn t.
what you want is tangent or curvature continuity. between the cone-like shape and the tip:
rebuild the red curve to have curvature-Continuety (inside the curve)
_rebuild 10 points, Degree 3 Delete Original
build a helping-Surface to have something to define tangent direction or the curvature.
_extrude
Then _loft between the green and the red surface edge.
choose option tangent at start, tangent at end